How should you chunk documents for RAG?

Chunk along the document's structure — headings and sections — rather than blind fixed-size windows that cut sentences and split tables. Keep the document title and section path attached to each chunk so it makes sense in isolation. Aim for chunks big enough to hold a complete idea but small enough to be specific; some overlap helps continuity. Good chunking is one of the highest-leverage RAG decisions: a chunk that carries its own context retrieves and reads correctly on its own.