Screenshotting some of the Jolie Cabinet Guide for you to download and peruse. How do you prep?
I have painted both with doors on and off. The more doors you have, the easier the project is if you remove them. Being organized at this point will help when it is time to put them back together! We highly recommend cleaning kitchen cabinets well in order to eliminate anything that may cause adhesion issues.
Starting with paint on the backs of the cabinet doors will help identify any potential issues on the fronts!