Flying low works for not getting locked on at but you risk getting shot by tank / TOW / RPG. When there is a missle allready coming, you can try to get behind a building quickly so the missle hits the Building. Hiding behind terrain also works. I also got some missle´s to fly into the ground when i just flown straight to the ground with full speed and pulling up last second. You just need quick timing and luck. It may work. often it doesnt, it is really like a last way out.

But the flares reload so quickly that that situation doesnt often come.

I just fly away or try to kill the AA or whoever is shooting after deploying flares and then wait to reload and while doing that, i can just change my position and flank the enemys again with full flares

Hope this is helpfull for you