Buy the zephyr or dalton and fly around in circles ! DONE
seriously, learn how your guns aim so if the gunner calls which way to face know how to position the lib in a way he can aim, same goes for tail gunner if hes AA especially, know how to react and position properly.
Learning a rapid landing is useful aswell, needs pratice but basically fly at the ground, pretty steep angle last minute pull hard up while pressing your space key to ascend, should just hit you into the ground but not damage you.
Usual health or auto repair upgrades, 1 level of decoys are very good as I can imagine soon enough every ESF will have lock on missiles and finally don't neglect the performance upgrades be it speed or maneuverability, both will be useful just depends on what you prefer.
[PCG]Mnemi - Terran Republic - Miller EU