My $.02 -- Go offline, set your ammo to the max in arena settings, take off and just keep shooting down the drones until boredome sets in. I know they are not very exciting targets, but you get used to bullet drop and get to see just how high you need to aim with each type of weapon to get hits, as well as the extra lead needed in a banked turn, etc. You'll eventually be able to hit planes that are too far under your nose to see when you pull the trigger (in fact, in most turing "deflection" situations this is required, particularly with Russian or German guns).
Also, work on getting kills at 300, then work your way into longer shots (again, with Russian or German planes this might be you maximum for reasonable results, just like 400 - 500 for allied aircraft). You can still get hits at longer ranges, just not too many kills.
Charon