Hello everyone. Sorry it's been so long since the last post.
The Jazz Academy from Jazz at Lincoln Center has put together a series of videos to help you learn how to warm-up and how to practice. Notice, none of them talk about practicing IN REHEARSAL. Warming up and practicing occur BEFORE rehearsal begins. Here is a good video on the basic concepts of warming up, aka getting your embouchure ready for practicing or performing.
Hopefully, that will help you to better understand the concepts.
The following video also talks about warming up, but also isolates the concept of long tones, and then adds on the technique side of practicing.
Please post a comment with your thoughts. If you have a question, feel free to post that as well. I'd like this to become an open dialogue for all of us to learn together!