I don't think looping is necessary. Just like any dogfight, it's all about approaching your opponent from the right angle, either on his tail or on his side. You should also get accustomed to not losing him; remember to look where your pilot's head turns. If you head towards that direction but still don't see him and your pilot looks the other way, it usually means you're flying too low. Gain some altitude and lower the nose of your plane now and then to scan the area. Approaching an enemy airplane from above is always better than approaching from below.
Another essential tip many people are unaware of: In balloon missions, always destroy the A/A guns before you do anything else. Yes, it is possible.
With a fighter pilot for a father, I must have SOME useful genes in me!
I never figured out what to do in strafing missions. After the first year when things get difficult, my plane is always shot down no matter what strategy I try.