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How to Use ChatGPT: Prompts and Advanced Features

How to use ChatGPT goes far beyond typing a question — this complete guide covers prompt engineering, practical use cases, custom instructions, model choice, Canvas, and custom GPTs.

How to Use ChatGPT: Prompts and Advanced Features

ChatGPT has moved from a novelty to a genuine productivity tool for millions of people — writers, developers, researchers, students, marketers, professionals of every kind. But most users approach it the same way: type a vague question, get a mediocre answer, conclude it’s overrated. The real value lies in prompt structure — the practice of framing requests in a way that consistently produces specific, usable results. For a broader walkthrough, our Complete Guide to Software and Apps is a good next read.

Once you understand the patterns that make prompts work, ChatGPT stops feeling like a lottery and starts feeling like a capable collaborator. This guide covers how to actually get there.

The anatomy of a good prompt

Four elements make a strong prompt: role, task, context, and format.

  • Role: what perspective to adopt — “Act as a senior marketing strategist”
  • Task: what you want done — “Write a 5-email onboarding sequence”
  • Context: background the model needs — “The product is a B2B SaaS tool for small accounting firms”
  • Format: what the output should look like — “Short paragraphs, no bullet lists, under 150 words per email”

You don’t need all four every time. Simple factual questions need very little structure. But any creative, analytical, or writing task benefits from at least task + context, and usually format too.

The difference between “Write me a blog post about email marketing” and “Act as a B2B content strategist. Write a 700-word blog post about email marketing for e-commerce founders. Focus on list segmentation and abandoned cart sequences. Use a practical, direct tone with numbered tips. Avoid generic advice” — that gap illustrates why prompting is really just communicating intent precisely.

Iterative refinement — the most underused technique

Treat the first response as a draft, not a final answer. After any response, follow up with specific feedback:

  • “Make the second paragraph shorter and more direct”
  • “Add a concrete example for the segmentation section”
  • “Give me three alternative versions of the opening line”
  • “Rewrite in the tone of a conversation rather than an article”

ChatGPT holds the full context of the conversation and applies follow-up instructions precisely to what it just produced. Prompt → response → refine → respond → refine again. This is how productive users consistently get high-quality output rather than one-shot responses.

Practical use cases — step by step

Content drafting: provide topic, target audience, tone, length, and any specific points to cover. Ask for a draft, then use follow-ups to improve sections. If you have existing content you want to match in style, paste a sample paragraph and ask ChatGPT to match that voice for the new piece.

Summarising long documents: paste the text and say “Summarise this in three bullet points” or “Extract the five most important decisions from this.” For documents longer than the context window, split into sections, summarise each, then ask ChatGPT to synthesise the section summaries into a final overview.

Brainstorming: describe the problem or goal and ask for ten ideas, twelve angles, or eight different approaches. After the initial list, pick the two or three most interesting and ask for further development. “Ten unusual product names for a sustainable water bottle brand targeting Gen Z” produces better results than “Give me some name ideas” — specific creative constraints unlock better output.

Code assistance: paste a function and ask what it does, what’s wrong with it, or how to improve it. Describe a function in plain English and ask for an implementation in your language of choice. Paste an exact error message and ask for an explanation. Specifying the language, framework, and version reduces hallucinations significantly.

Research and explanation: ask ChatGPT to explain complex topics in plain language (“Explain transformer architecture as if I have a software background but no ML knowledge”), ask for analogies, or ask it to break down a technical process into sequential steps. This is powerful for learning — but ChatGPT is not a factual reference. It can generate plausible-sounding but incorrect information, especially for specific statistics, citations, and recent events. Use it to understand concepts, explore frameworks, and get explanations; verify specific factual claims from primary sources.

Email and communication drafting: paste the context and ask for a draft. Specify the relationship (colleague, client, manager), the desired tone (formal, friendly, assertive), and the goal (request, apology, follow-up, decline). This saves significant time on the repetitive professional writing that fills calendars.

Custom Instructions and Memory

Custom Instructions are one of the most impactful features for making ChatGPT consistently useful across many sessions. Click your profile name → “Customize ChatGPT” → Custom Instructions.

The first field asks what ChatGPT should know about you. Enter relevant context about your role and goals: “I am a freelance UX designer working primarily with SaaS startups. My clients are usually non-technical founders.”

The second field asks how it should respond. Specify response style: “Be direct and practical. Avoid lengthy preamble. Use short paragraphs. When giving examples, use concrete scenarios rather than abstract descriptions.”

These instructions apply to every conversation automatically, so you stop getting generic responses and get ones calibrated to your work and preferences from the first message.

Memory (available in ChatGPT Plus) allows the model to remember facts across different conversations — your name, role, preferences, ongoing projects. Enable or review what it remembers: profile → Settings → Personalization → Memory. You can also tell it directly: “Remember that I prefer metric units” or “Remember my company’s main product is X.”

Model comparison — which one to use

Model Best for Access
GPT-4o Most everyday tasks — writing, summarising, coding, analysis. Fast and versatile. Free + Plus
o3 / o3-mini Complex reasoning — multi-step maths, logic problems, difficult code debugging, research analysis. Slower but noticeably better on hard problems. Plus (limited)
GPT-4o with tools Tasks requiring web search, code execution (Data Analysis), or image generation simultaneously Plus
Custom GPTs Specialised recurring tasks with specific knowledge and instructions built in Free + Plus

In practice: use GPT-4o for everything by default. Switch to o3 when you have a genuinely hard problem — complex code debugging, multi-step reasoning, research that requires careful analysis. The slower models cost more (in terms of message limits) but produce meaningfully better results on tasks that challenge GPT-4o.

Advanced features worth knowing

File uploads: upload a PDF, spreadsheet, image, or document and ask ChatGPT questions about it. “Summarise the key findings from this research paper.” “What are the three largest expense categories in this spreadsheet?” “Describe what’s happening in this chart.” This changes how you use it for research and data work — paste a document, start asking questions.

Image generation (DALL-E, Plus): describe an image and ChatGPT generates it. Specify style (“photorealistic,” “flat illustration,” “watercolour”), composition, subject, and mood. Iterative refinement works here too — generate, provide feedback, regenerate with adjustments.

Advanced Data Analysis: upload a CSV or Excel file and ask ChatGPT to analyse it, generate charts, run calculations, or identify patterns. It writes and executes Python code in a sandbox to produce the results — no coding knowledge required.

Custom GPTs: pre-configured ChatGPT instances tailored for specific tasks. Find them in the GPT Store (home screen) or build your own through “Explore GPTs” → “Create” — define instructions, upload knowledge files, configure capabilities. For teams needing consistent ChatGPT output for a specific workflow, a custom GPT with uploaded brand guidelines and product documentation delivers far more focused results than a general conversation.

Build a prompt library — the habit that compounds

Maintain a personal prompt library — a simple document where you save prompts that produced consistently good results. Over time, this becomes a set of reliable templates for your most common tasks: a content brief template, a code review prompt, a meeting summary format, a client email skeleton.

When you need that task done again, open the library, copy the template, fill in the specific details, get a high-quality result in seconds. This systematic approach transforms occasional useful outputs into a reliable workflow. Our guide on using Notion covers building a personal knowledge base where a prompt library fits naturally alongside notes and project trackers.

One ethical note worth addressing: using AI assistance for writing and analysis is increasingly normal and accepted, but transparency norms vary by industry, employer, and context. Academic institutions have specific policies. Some publications require disclosure. Using ChatGPT as a drafting tool while applying your own expertise and editing produces work that combines AI speed with human quality — a genuinely powerful combination when applied honestly and appropriately to the context.

Prompting patterns that work across tasks

Beyond the basic four-element framework, several specific patterns consistently produce better results:

“Few-shot” examples: show ChatGPT examples of what you want before asking for the output. “Here are two examples of the tone and format I’m looking for: [Example 1]. [Example 2]. Now write a third one about [Topic].” This is the fastest way to communicate a style that’s difficult to describe verbally.

Chain-of-thought prompting: add “Think through this step by step before giving me your answer” for complex problems. This prompts the model to reason through the problem before committing to a response, producing significantly better results on multi-step reasoning tasks.

Constraints as guardrails: specify what you don’t want as clearly as what you do. “Don’t use the word ‘leverage’.” “Don’t include a summary section.” “Don’t suggest X approach — we’ve already ruled it out because of Y.” Negative constraints are often more effective than positive ones for shaping output away from generic patterns.

Ask for options: instead of asking for one answer, ask for multiple versions. “Give me three different ways to open this email, each with a different tone.” “Write two versions of this paragraph — one formal, one conversational.” Comparing options is often faster than iterating on a single version.

Structured output requests: ask for specific formats — a numbered list, a table, a JSON structure, a markdown document. “Give me this as a comparison table with three columns.” “Format this as a JSON object with these keys.” Structured outputs are immediately usable without reformatting. Our guide on How to Use Google Drive covers an adjacent issue.

What ChatGPT is genuinely bad at — knowing the limits

Using it effectively means knowing when not to use it:

  • Real-time information: by default, ChatGPT’s training has a knowledge cutoff (check the model’s stated cutoff in Settings). For current events, recent research, or live data, enable the web browsing tool or use a search engine for verification.
  • Factual precision: ChatGPT confidently states incorrect facts. Never cite it as a primary source. Use it for concepts and frameworks; verify specific data, statistics, and citations elsewhere.
  • Long documents that exceed the context window: the context window limits how much text can be active in one conversation. Very long documents need to be split, summarised in chunks, or processed using the file upload feature in multiple parts.
  • Consistent persona over many sessions (without Memory): without custom instructions or memory, ChatGPT starts fresh each conversation. It won’t remember your preferences, your past work, or your ongoing projects unless you tell it again or have set those up in Custom Instructions.
  • Tasks requiring legal or medical professional judgment: ChatGPT can provide information about legal and medical topics, but its outputs are not a substitute for professional advice. It’s useful for understanding concepts and framing questions; a professional should review anything consequential.

ChatGPT is most valuable as an accelerator for your own thinking and expertise rather than as a replacement for it. The people who get the most from it consistently are those who bring clear intent, specific context, and critical judgment to review the output — treating it as a fast first draft that they then improve, rather than a finished product they accept uncritically. See also How to Use ClickUp for a related case.

Nikolas Lamprou

Nikolas Lamprou (MSc; GCFR, SC-200, Security+) has been working with computers professionally since 2009 — starting with web development and e-commerce, and moving into cybersecurity over the years. Based in Greece, he brings over 15 years of real-world IT experience to SolveTechToday, where he writes about Windows fixes, software reviews, security tools, and AI applications. His goal is straightforward: cut through the noise and give readers clear, honest guidance on the tech decisions that matter.

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