Usage of your radar is normally a good source for finding enemy craft. Looking in the distance of the battle screen is a more succesful method as you have a longer range here.
Catching enemy craft by surprise is a good way of getting the upper hand on them.
Smaller enemies can be destroyed by being run over at high speed. Using this method will save using up missiles unecessarily.
Usage of mines especially indoors is a good way of destroying any persuing enemy craft. They will continue along your path until they meet a bitter end by manouvering over your mines.