I allways have breakfeast (love my food,) then wait a bit before doing any excercise.
I don't have any set routines or training "regimes" for in the morning.
I like to mix it up to keep it interesting. Might go for a long run, sprint session at a track or on hilly fields or try the PJFT, go swimming, do various sets of push-ups (weighted back-pack, close arm, wide arm, marine style, plyometrics, feet raised) or go to the gym and do some deadlifts, squats & pull-ups.
If i've done a weights session or some bodyweight circuits in the morning, then i will run or swim in the afternoon, and visa versa, remembering to have rest days.
My thinking is that by doing different workouts all the time, it keeps your muscles guessing and makes you improve more!