10 prompts I use every day. Six months of testing across Claude, GPT-4, and Gemini narrowed it down to these.

Universal Rewriter: "Rewrite this text for [audience]. Maintain all key information but adjust tone, vocabulary, and structure. Target style: [casual/professional/technical]. Text: [paste]”

Code Review Assistant: “Review this code for: bugs, security vulnerabilities, performance issues, and readability. For each issue found, explain WHY it's a problem and provide the corrected version. Code: [paste]”

Meeting Prep Generator: “I have a meeting with [person/company] about [topic]. Generate: 5 talking points, 3 potential objections they might raise, and 2 smart questions I should ask. Keep each under 2 sentences.”

Email Style Matcher: “Here's an email I received: [paste]. Draft a response that matches their communication style, addresses all their points, and moves toward [desired outcome]. Max [N] words.”

Decision Matrix Builder: “I need to choose between [Option A] and [Option B] for [context]. Create a weighted decision matrix using these criteria: [list]. Score each option 1-10 with a brief justification. Recommend the best choice.”

Content Multiplier: “Take this blog post and create: 3 tweet-length takeaways, 1 LinkedIn post with the key insight, and 5 bullet points for an email newsletter. Maintain my voice: [describe]. Original: [paste]”

Competitive Intelligence: “Analyze [competitor] based on publicly available info. Structure: strengths, weaknesses, market positioning, pricing strategy, and 3 opportunities they're missing that I could capitalize on. My business: [brief description].”

Expert Consultant: “You are a senior [role] with 20 years of experience in [industry]. You give direct, actionable advice. You always ask clarifying questions before diving into solutions. You back recommendations with reasoning. Never use corporate buzzwords.”

Debug Assistant: “Analyze this error/bug: [paste details]. Provide: 1) Most likely root cause, 2) Step-by-step debugging approach, 3) Potential fix with code, 4) How to prevent this in the future.”

Socratic Tutor: “I want to learn [topic]. Instead of explaining everything at once, ask me questions that guide me to understand the concept myself. Start with the most fundamental question. Adjust difficulty based on my answers. If I'm stuck, give a hint, not the answer.”

The formula underneath all of them: Role + Context + Task + Format + Constraints.

Leave any of those out and the model fills the gap with the most average answer it can produce.