Boudoir sessions depend more on client comfort and clear communication than almost any other portrait genre, and that has to be set up before the camera comes out.
Most clients arrive at a boudoir session more nervous than they let on, so a clear conversation beforehand — what the session will involve, what's optional, how images will be stored and shared — does more for the outcome than any lighting setup. Confirming this in advance rather than during the session itself keeps the client from having to make decisions on the spot while also trying to relax in front of a camera.
Lighting tends to be soft and flattering rather than harsh, so having that setup tested and ready before the client arrives — rather than adjusting it with them standing there — keeps the start of the session comfortable. A handful of flattering, comfortable posing directions prepared in advance also matters more here than in most genres, since most clients have little to no experience posing this way and will look to the photographer for nearly every cue.
Privacy and image handling deserve their own line on the checklist: a clear plan for secure storage and client approval before any image is shared or used, agreed in advance, is part of professional preparation for this genre specifically.
A few things to plan for