ive heard about not turning them up all the way.....dunno how true it is but ive heard that you should only listen to your speakers at around half volume so the cone has time to break in a bit.
ive done a few installs (entered one spl comp) and depending on the car model ive found the biggest pain in the ass with door panels is getting the damn horseshoe ring off the window crank (manual rollup, never done automatic). Also, be careful about removing the panel so you dont have to replace the door plugs.
also, sound deaden your doors, itll make your speakers sound way better