Where to take the solo next

The encore.

Eleven reviews closed. The LLM world is wider than one set can hold. Here are four places to keep playing — chosen by us, free where it says so.

1. Anthropic's prompt engineering guide

   The clearest first reference for writing better prompts. Honest, no hype, written by people who build LLMs every day.

   freereference
   ↗docs.anthropic.com
2. OpenAI's prompt engineering guide

   The other half of the picture. Same techniques, different examples, occasionally different recommendations. Read both and triangulate.

   freereference
   ↗platform.openai.com
3. OpenAI Evals

   An open framework for testing LLMs against fixed benchmarks — the natural next step once you've played the whole set. Watch a few existing eval suites before you write your own.

   freepractice
   ↗github.com
4. Anthropic Cookbook

   Practical patterns: agents, tool use, RAG, evals, structured output. Each recipe is one Jupyter notebook you can clone and adapt.

   freepractice
   ↗github.com

We left a lot off this list on purpose. Five things you'll actually use beat fifty you'll skim. If something brilliant is missing, tell us — we'll review it for the next refresh.