FFA - Free For All is a type of round in which every player competes against the other players. The primary goal is to get the most kills before the round ends, although occasionally good players also compete for longest life, longest killing streak, and biggest multi kill. Bad players think FFA is a time to mess around. An FFA round ends after either the timer runs out or a player attains a certain number of kills. The conditions under which the FFA round ends are set by the person who hosts the server.
FFA is simply about getting the most kills out of everyone.
1) Spam: Be sure to spam many shots into the distance because you never know what it can do. If you're a bomber or a loopy this is especially effective. Spamming mines with explodet is also good.
2) Bars: FFA is all about the bars. For those of you who don't know, when you kill, you get colorful bars above your plane: 1 orange, 2 oranges, 3 oranges, 1 silver, 2 silvers, 3 silvers, 1 gold, 2 golds, 3 golds. 3 golds being the best here. Anyway, bars increase your power, speed, agility and armor, so when you have them, it is easier to kill. This is vital to being superior in FFA: when you get the bars, you can get more kills.
3) Try not to die. When you die it takes away your bars and therefore makes it harder for you to kill.
4) Take cover behind rocks and such so that you can kill without being killed.
5) Green perks: Repair drone is by far the most popular because you can keep those awesome bars for longer. However if you really kill better with another green perk, feel free to use it and collect the small health packs. If you don't use repair drone, you have to kill even more to get these health packs and stay alive.
6) Kill stealing: Although it will almost certainly make people angry, a great strategy is to "steal kills." In other words, don't feel the need to deplete each plane's entire health source by yourself. Go for the smoking planes; the darker the smoke is, the more likely you can get an easy kill.
All in all, FFA takes you down to your raw individual skill. It does not take any team play but it's a great place to start to hone your skills before you enter the land of complex altitude strategy. FFA can also help you find out what plane you will use best in competetive play.