Agree with everything posted thus far. Here's some points from the Dicta Muzzy:
1. Make sure your views are set correctly and make sure your view buttons are set so you can fly while looking in different directions. If you have a joystick with a hat switch, set the "up" view for your off hand, so that while holding it down you will be able to use your hat switch to view the up/left, up/right, up/back, and up/front views.
2. Fly in the Dueling Arena. You can experiment freely without fear of affecting your score or perk points (not that score matters all that much anyways) and you will get more combat time in.
3. Practice your gunnery on offline drones. Guns are different for every bird, so practice for every plane you fly.
4. Read up on every plane you might face, and take the time to do check rides in the TA or offline so you know what you are up against.
5. Learn throttle and dive management. Overshoots and blacking out are two of the most common mistakes you can make. Throttle back, learn how to dump speed when you need to, and practice flying on the edge of stalling and blacking out. You want the edges of your screen to go black, but you never want to see everything go dark.
6. Convergence is a matter of preference, but remember your best shots are going to come at 400 yards or less.
7. Learn to think in three dimensions. Being able to loop and roll effectively and learning to track your targets while doing so will give you a big advantage.