these are pretty obvious but heres a few things that may help:
make sure you sleep every day even if its in a vehicle, even if its short and even if its light sleep. (its better to sleep from 4 to 6 in copenhagen than not at all)
if you have time between time zones try and adjust your clock 1 hour per 2 nights in the direction of the time change.
as a musician youre probably getting to sleep late so try and make your hours count, sleep in when you can.
try not to add much fun/touristy things to the menu each day - stay rested
remember that alcohol decreases quality of sleep
maybe try using melatonin to keep your sleep on schedual with the time zone youre in?