Hint: Time Attack
Current Rating: Not Rated
If your heat is low and you're flying in to attack a squad, try to catch them while the leader is flying at an angle, and spray the entire group. This works well with Rival's machine gun. You can catch any scraglers with a shot of Firework Missiles to the corner of each formation.
If you'd like to do it in reverse, lock the closest Leader to the targetted leader of the major group (if none, just target the leader), because often, more than one group will fly in squadron with another small group. Fire missiles, spray to the corners or the part of the group that's farthest away from the tip.
Fire randomly after you shoot any missiles off on a major group. Because it's hell trying to catch the little guys you've missed, cursing yourself as seconds tick away.
Sometimes, if there's a lot of groups scrambled nearby, it's easiest to just unlock your targetter by holding Triangle, spray in any direction you see a fighter fly by, and hope you hit all of them and don't need to hit any scragglers.
There's always two formations of the Chevalier modeled ships that constantly are on the offensive. While you're targetting a far-away group, simply turn your targetter towards them instead. Shoot them while still heading towards the group, without switching targets, to save time. Then just kill them when you have to, seeing as they love to play Dogfight, and it's really annoying.