WHAT'S IN A NAME
The first problem with warm-ups is the name "warm-up." This name contains two problems. First, it implies a brief period of playing just long enough to get the "chops going." Most students underestimate how much warming-up is needed before they are truly ready to perform well. Second, the name "warm-up" tends to direct one's attention to the physical state of the embouchure. While it is necessary to be aware of how your face feels, I think it is more important to focus your attention on a musical goal. There are many days when the chops don't feel good but you still have to perform. Professionals don't have the luxury of playing only on "good chop" days.
It is better to think of your day's first notes as a daily routine or daily maintenance program. That routine is your first and best chance to reinvigorate good playing habits which can then be transferred over into your practicing and performance.
ON THE CLOCK
Before you begin your daily routine, decide how long it will be. Keeping yourself on schedule will help you to maintain focus and a sense of purpose to your efforts.
If you're running late and the rehearsal is fast approaching, the length of your warm-up is pretty much decided for you. Even in a short "emergency" warm-up, try to cover a variety of material. Don't force the embouchure to do something it isn't yet ready to do. Spend those few moments trying to get some relaxed resonance in your sound.
MIND AND BODY
The warm-up is not just for your body, it is also for your mind. Playing well takes a great deal of relaxed concentration. For most people, this kind of concentration doesn't happen automatically. Your daily routine should act as a stimulus which evokes the response of mental focus. For this reason, it is important to avoid the temptation to daydream during your warm-up. Whatever patterns you choose, play them with a sense of musical direction. Try adding slight variations on your warm-up patterns to keep things interesting. Have a metronome turned on and play exactly in time with it. Don't mindlessly grind through the same old patterns with minimal attention to quality. If time permits, repeat something to improve it.
BRIDGING THE GAP
I have noticed both in my own playing and in that of my students, a clear separation between "warm-up" playing and other playing. Ironically, it is easy to develop all these good habits during the warm-up and then abandon them once we leave our routines and dive into some music. Therefore it is important to "bridge the gap" between daily routine and daily performance/practice. Perhaps you can insert fragments of upcoming music into the texture of the warm-up. For example, slow down those rapid runs from William Tell Overture and use them as a relaxed tonguing routine. Do this regularly and the habit of relaxed tone production will begin to carry over into your performance of the excerpt.
Here is a link to the download page for my basic daily routine (tenor or bass trombone).