Think about strategy, don't think about aim. Learn to fire by instinct, but always consider the "big picture" of battle. Know where players are vulnerable to surprise attacks, and know what spots are easy to defend. Playing for both teams, rather than having a preference, helps you learn. If you ever think "I'm exposed to a sniper when I cross this alleyway", remember that. Next time you're on the other team, get a sniper rifle at cover that alleyway.
When you shoot, don't focus too much on the position of your finger on the thumbstick. Just make sure you always hold the controller in the same grip, then use the force.
When you shoot, don't focus too much on the position of your finger on the thumbstick. Just make sure you always hold the controller in the same grip, then use the force.