Learning by doing. Hop in Crash, crash, crash, crash, crash........
Then start with segments for example, Practice gun runs till you master them and move on to bombs.
Keep the boring stuff for later (Navigation :music_whistling:etc.) That keeps you interested (At least it did it for me). It does require quiet a bit of dry theory tho if you wanna get good, i belive.
The in-depth things come almost by themselfs after a good load of flight hours.
Also setting yourself custom missions up is a realy good way i think, if you wanna learn how to defeat a SA6, put one on the map start in the air and practice till your fingers bleed.