How to Use Claude

Go to claude.ai and sign in. Type anything in the text box and press Enter. No special syntax, no commands to learn. Claude understands natural language.

Start with something you can evaluate: “Explain what a product roadmap is in 3 sentences” or “Write a polite email declining a meeting invitation.” This lets you calibrate Claude’s tone and quality before relying on it for important work. You will notice the writing feels more natural and less formulaic than other AI tools.

Claude does not know who you are unless you tell it. One to two sentences of context transforms the output from generic to tailored.

Before asking for help, set the scene: “I am a marketing director at a 200 person B2B SaaS company. We sell project management software to mid market companies.” Now every response accounts for your role, company size, and audience. The more relevant context you provide upfront, the less editing you do afterward.

Claude defaults to well structured prose. If you need something different, say so: “Give me this as bullet points,” “Put this in a table,” “Keep this under 100 words,” or “Write this as a Slack message, not an email.”

You can also specify tone: “Be direct and skip the caveats,” “Write this for a technical audience,” or “Match a casual, conversational tone.” Claude adjusts immediately without losing quality.

Drag a file into the chat window or click the attachment icon. Claude accepts PDFs, Word docs, spreadsheets, images, and code files. On Pro, it handles documents up to roughly 3,000 pages in a single conversation.

This is Claude’s single most underused feature. Instead of reading a 40 page report yourself, upload it and ask: “What are the three most important findings?” or “Does this contract have any clauses that are unusually one sided?” Claude reads the full document, not a summary of it.

When the first response is close but not right, tell Claude what to change: “Make it shorter,” “The tone is too formal,” “Add specific numbers,” or “Focus more on the risks.” Claude retains the full conversation context and adjusts.

Most useful outputs come from two to three rounds of refinement. Think of it as a conversation with a colleague who drafts fast and revises willingly, not as a search engine where you type once and hope.

Projects are persistent workspaces available on Pro and above. Create one for any ongoing effort: a product launch, a content calendar, a codebase, or a research program.

Inside a Project, you can upload reference documents, set custom instructions (“Always write for a technical audience,” “Our fiscal year starts in April”), and start multiple conversations that all share the same context. This means you set up your background once and Claude remembers it across every conversation in that Project. It is the single biggest time saver for regular Claude users.

Claude is more willing than most AI tools to give genuine critical feedback, but you need to explicitly ask. By default, it leans toward being helpful and positive.

When you want real criticism, say so directly: “Be genuinely critical, not encouraging,” “Tell me what is wrong before telling me what is right,” or “If this argument is weak, say so.” Claude will flag problems, identify gaps, and point out weak reasoning when given permission. This is one of its most valuable capabilities for anyone drafting important documents, proposals, or strategies.

For multi step problems, Claude can think through its reasoning before responding. On Opus 4.6, this happens adaptively. For particularly complex questions (strategy decisions, debugging tricky code, analyzing conflicting data), you can prompt it explicitly: “Think through this step by step before giving me your recommendation.”

Extended thinking is most valuable for decisions with trade offs, code that involves multiple interacting systems, and analysis where the obvious answer might be wrong. For simple questions, it adds latency without benefit.