Reality Log
Written the same day, before it can be argued with

A reality log is the simplest intervention in coercive-control recovery: write it down the same day, in short sentences, before the account can be argued with. Over weeks the pattern becomes visible without the client having to defend any single entry.
Keep it safe
If there is any risk in a written record being found, keep the log in session or in a place the client controls entirely. Safety comes before documentation — always ask before sending this one home.