How Many Projects Should I Create? Do I Need One for Every Use Case?
Start with one and expand gradually — that's the best strategy.
First Project: general workspace. Include your most basic work background (who you are, work nature, output preferences). This Project works for 80% of daily work tasks without needing to be tailored to any specific context.
When to create a second Project? When you have a category of work that differs significantly from your general workspace in these ways: needs a different tone (e.g., your general workspace is for internal communication, but you also have client-facing work requiring a more formal tone); needs a specific set of background documents (e.g., all documents related to a long-term client or a large project); or needs Claude to play a different role (e.g., a learning Project where you want Claude to act as a teacher rather than an assistant).
Practical recommendation: most workplace users are well-served by 2–4 Projects. Don't try to create a Project for every task type from the start — use one general one, and split it out only when you find it insufficient.
Are There Size or Format Limitations for Documents Uploaded to the Projects Knowledge Base?
Yes, but most workplace documents fall well within the limits.
Supported formats: PDF, plain text (TXT), Word documents (DOCX), code files (Python, JavaScript, etc.), Markdown (MD). Excel and PowerPoint formats are not directly supported currently — if you need this content, export it to PDF or copy it as text first.
Size limits: each Project's knowledge base capacity is approximately 200K tokens (equivalent to roughly 150,000 words of text). Most workplace documents are well within this limit, but for very long documents you may need to split them or upload only the most relevant sections.
Practical tip: don't upload every document you have — only upload what you'll genuinely use in conversations within this Project. Too many documents actually make it harder for Claude to find relevant information, potentially degrading output quality. 3–5 core documents per Project is usually the optimal balance.
I've Set Up Custom Instructions, but Claude Doesn't Seem to Follow Them Fully. What Can I Do?
This is a very common issue with several possible causes and solutions.
Cause 1: Custom Instructions are too long or too vague. If your Custom Instructions exceed 500 words, or contain many vague qualifiers like 'sometimes' or 'in most cases,' Claude may not correctly prioritize your rules in some conversations. Fix: move your 3–5 most important rules to the very top of Custom Instructions, making them explicit and unambiguous.
Cause 2: In-conversation instructions override Custom Instructions. Within the same conversation, Claude generally prioritizes what you explicitly say over Custom Instructions defaults. If you say 'write this in English' mid-conversation, Claude will write in English even if Custom Instructions say 'use Traditional Chinese.' This isn't a bug — it's by design, with real-time instructions taking priority over background settings.
Cause 3: Updated but not applied. After modifying Custom Instructions, already-open conversations don't update — only newly opened conversations apply the new settings. If you changed your settings and see no difference, try opening a completely new conversation.
Fastest way to test: in a newly opened conversation, ask Claude 'what are your current settings? What information do you have about me?' It will usually summarize the Custom Instructions it has read, confirming whether your settings are working.
What's the Difference Between the Projects Knowledge Base and the Notion Plugin? Which Should I Use for Work Documents?
Both let Claude read your documents, but they suit different scenarios — the choice depends on how often your documents update and your management preferences.
Projects knowledge base advantages: set it up and forget it — upload once and every conversation automatically reads it; documents are indexed by Claude in a more efficient way with stronger search capabilities. Disadvantages: documents need manual updating — if your work documents change frequently (e.g., weekly-updated data), each change requires re-uploading to Projects, which is cumbersome.
Notion Plugin advantages: Claude reads the latest version from Notion every time, ideal for frequently updated documents; no manual syncing needed. Disadvantages: each conversation requires explicitly telling Claude 'go read my Notion page on X' — there's an operational step; requires Claude Pro with Notion integration enabled.
Recommended division: stable, infrequently-updated documents (company guidelines, personal background, product specifications) → Projects knowledge base. Frequently updated work documents (weekly reports, meeting notes, live project documents) → Notion, accessed via Notion Plugin. Both can be used simultaneously — they're not mutually exclusive.
If you have Claude Pro but have never touched Projects, you're not alone. Based on user feedback, a significant portion of Pro users open a new conversation every day, re-introduce themselves, and re-explain their work context — because they don't know that Projects can set all of this up once and carry it forward automatically.
This article is a hands-on beginner's guide that walks you through building your first Work Project in 30 minutes, so every Claude conversation starts from 'it already knows who you are' rather than from scratch.
Why do so many people overlook Projects? Two main reasons: first, it isn't prominently placed — in Claude.ai's left sidebar, you need to find the 'Projects' option, which not everyone notices. Second, the name 'Project' makes people assume it's for large-scale undertakings, when in reality it's more like a 'fixed workspace' between you and Claude — no matter what work you use it for, Projects' core value is 'letting Claude remember your background settings.'
Have you had this experience: every time you start a new conversation, you spend 2–5 minutes telling Claude 'I'm a marketing manager, I'm in tech, I prefer direct communication, please reply in Traditional Chinese…' and then the next conversation you have to say it all again. Projects plus Custom Instructions is the solution — you only need to say it once, and after that, every conversation you open in this Project automatically starts with Claude knowing these settings.
There are three key differences between regular conversations and Projects:
Memory scope is different: regular conversations have no cross-conversation memory — what happened in today's conversation is forgotten tomorrow. Projects, through Custom Instructions and uploaded knowledge documents, lets Claude automatically load your configured background information at the start of every conversation within that Project.
Knowledge base is different: Projects allows you to upload documents (PDFs, text files, code, etc.) that become the Project's 'knowledge base.' Claude can read these documents in every conversation within the Project without you needing to re-upload them each time.
Organization is different: you can create multiple Projects, each with different purposes and configurations. For example: a 'Daily Work Project' with your role settings and work preferences; a 'Client A Project' with all background documents related to that client; a 'Learning Project' with materials on topics you're studying.
Follow these steps to build your first Work Project in 30 minutes:
Step 1: Find the Projects feature. In Claude.ai's left navigation bar, find the 'Projects' option (usually above or alongside the conversation list). Click 'New Project.'
Step 2: Name your Project. Naming it after your work role or primary use is recommended, such as '[Your Job Title] Daily Work' or your name plus 'Workspace.' A clear name helps you identify it later, especially once you have multiple Projects.
Step 3: Write your Custom Instructions. This is the most important step. Find the 'Custom Instructions' or 'Instructions' field in Project settings and write your work background. Include four elements: who you are (job title, industry, work nature), your preferred output format (Traditional Chinese, bullet points, length range), background keywords (company abbreviations, common terms), and what you don't want Claude to do (no disclaimers, not too academic, stop asking many follow-up questions).
Step 4: Upload your core background documents. If you have frequently referenced documents (company SOPs, product descriptions, past work templates), upload them to this Project's knowledge base now. After uploading, every conversation in this Project can access these documents without re-uploading.
Step 5: Open your first conversation and test the setup. Start a new conversation within this Project, test a few questions, and confirm Claude correctly understands your background settings. If anything seems off, return to Custom Instructions to adjust, retest, and repeat until satisfied.
Many people writing Custom Instructions for the first time either write too little (insufficient information) or too much (stuffed with edge-case explanations that leave Claude unable to find the key points). Here's an effective template format:
'My background: I am a [job title] working in [industry/company type], primarily responsible for [core responsibilities]. My primary audience is [the people or systems you work with].
Output preferences: Please reply in Traditional Chinese. Paragraphs shouldn't be too long; use bullet points for key information. Unless I request otherwise, keep responses under [your preferred word count]. No disclaimers or 'consult a professional' language needed.
Work style: I prefer getting to the point directly without much preamble. [Add any style preferences important to you]
Please don't: don't ask me many follow-up questions — give me a concrete answer or recommendation first, and I'll follow up if I need more.'
This format runs about 150–250 words, covering the core information Claude needs without being overly long.
After setting up Projects and Custom Instructions, the most immediate change is: every Claude conversation can reach effective working mode faster. No more re-introducing yourself, no more repeating preferences, no more needing to 'warm up' a conversation before getting genuinely useful responses.
The longer-term impact: as your Project grows richer (knowledge base more complete, Custom Instructions more precise), Claude's understanding of your work deepens — it becomes increasingly like an assistant that genuinely knows your work context, rather than a highly capable tool that knows nothing about you. This accumulated effect is something you'll truly feel only after several months.