I don't know if anyone posted these already:
-Don't fire explosive weapons until the armor is stripped. This little bit of patience will get your crew kills much quicker than when you're stuck reloading when your chaingunner just brought down the hull armor.
-When setting up ships, restrict yourself to just 1 explosive gun in attacking position. So on the Mobula, this would be two chainguns and one flak/mortar rather than one chaingun and two flak/mortar, the explosive weapons do extremely high damage when the hull is down, so it's much more important to get the hull down.
-Opponents see your flares and see your ship through clouds you flare, so don't use it when trying to go across a cloud you don't see behind.
-When chasing or having an advantage try to match the speed of your target to prevent you overshooting him.
-When fleeing or having an disadvantage, you can try to force an overshoot, by going right by him; even as a squid.
-When a team deathmatch starts, always fly towards your teammate before taking any further action. Do not under any circumstances charge the opponent head on without support.
-When fleeing, do not herd your opponents to your teammates, unless they explicitly tell you that you can do so. When you herd opponents towards your teammate, your teammate can come under fire, forcing him to drop whatever he was doing, making him even less capable of helping you.
-In CP, do not chase that goldfish/squid that is speeding away from the capture point.
-Always, and I really mean ALWAYS, talk with your crew before readying up.
-Always tell your captain what you are planning to do/doing.
-Always obey the captain's orders; this is imperative, because when you listen it is his fault when things go wrong rather than yours, that means the captain has less variables to deal with and he can learn from his mistakes a lot faster.
-When captains give repair commands, usually the closest engineer to the to be repaired object gets the job. If that engineer is overworked(is firing weapons or has to repair too many things) he needs to inform his crew so that the captain can either shift priorities or assign another engineer to the job.
-If a target is in firing range, first ask your captain if that is your current target; good captains will give explicit orders on who to fire on, it's imperative that you listen to that.
-Report any failures to comply to order to your captain. That means if your gun is reloading, your gun is out of arc or your gun is out of range you inform your captain so he can take the appropriate decision.
-Understand that while this is just a game, you wouldn't see anyone throwing the ball to the opponents in a basketball game either. Cooperation is imperative for your team to succeed and for you to play and enjoy the game to its fullest.