I think warming up should be consistent and used for preparing your mind, body, chops, fingers, and air for the task at hand. It doesn't have to be for extended periods of time, but it should be a time that you focus on and not just mindlessly blow / rush through. If at all possible, I try to play a bit in the mornings... and I usually start with arpeggiations down into the pedal tones. Then I'll do lip flexibility studies and focus on using my tongue and my air. Just a reminder for myself on what to do and how to properly do it. Hope this is a useful contribution... all players are different, and it's best to find a routine that works for each individual. Keith Fiala Trumpet High Note Help, Trumpet Lessons Online, Beginning Trumpet Lessons, Trumpet Books, Trumpet Resources - A trumpet players resource for lessons, courses, and materials to improve range, control, tone, improvisation, and technique!