If you're on the west side of the map, trees are your friends. Dodge between them, land under them. East side, valleys can help. Make the enemy focus more on maneuvering than aiming at you. North side... well... not much you can do there except run south or try and find a base. The big crater can help, it's got a few nice places to dodge through, but really, it's just a desert without much cover for the most part.
I've gotten decent at flying the gal through the trees and it's saved me at least once. Possibly more, but I can't guarantee some of those weren't due to help I was getting from teammates. Trees don't necessarily provide perfect cover, but it's damn hard to aim through them and the lower you stay to the ground the harder it is for the enemy to get into a position where you can't fire back upon them (if you have gunners.) The gal bank rate does seem to be a bit more sluggish since the last update though, but it's yaw rate seems either the same or boosted, so it's not too hard to adjust.
I had a really nice run in a Gal earlier with one other person. I'd fly him around to small outposts to capture them. Good practice for hot drops and evacs. Did my best to fly as close to the points as possible to let him jump out and then land and get deployed as fast as possible on the pickup. Ran into reavers at some point near Dahaka and while I dodged most of the dumbfire rockets, the guns were pretty accurate and one of them had A2A. I landed and tried to repair, got the health back up but then started getting hit hard so I tried to run again, but it was the desert so I had no luck and eventually died. My passenger managed to escape though. Good on him.
Flying the gal really is the most fun thing for me. I'm definitely pumping everything I've got into it after the wipe. Dislike the new crazy long timer, but I guess they give certs to get rid of most of it, even if they're expensive.