How do I train AI to write in my voice?

Collect 5-20 of your best pieces, ask the model to extract your patterns (sentence rhythm, vocabulary, opinions, openings), and turn that into a voice file you reuse as a system prompt, Claude Project, or custom GPT. With 3-5 good samples AI captures roughly 70-80% of your style, and every round of feedback sharpens it. Rules beat adjectives: 'never open with a question, short declarative first lines' works far better than 'be witty'.

A quick orientation. The real value is below: resources worth your time, from people who've actually done it.