Use Laser Weapons. The kinetic are woefully underpowered, and the Plasma have low projectile velocity, and thus require a fairly advanced user at anything outside short range.
Distance is always your friend. The enemies in the game generally have poor accuracy, with exception of the snipers, who have pinpoint accuracy, but typically engage at such long distances, even moderate movement is enough to evade their fire.
Aim Center-mass always. It's tempting to go for a headshot, but Aim Small, Miss Small.
Automatic weapons should not be fired in fully automatic unless the target is really close. Short controlled bursts, Let go 1-5 shots, ease off the trigger to get your sight picture back, and then let off another burst.
If you're caught out in the open, keep moving. Don't stop strafing left and right. If you have to sprint away from hostiles, don't sprint straight, perform the "Serpentine" maneuver, that is, sprint but make an S running pattern as you cut left and right relative to the enemy, while also running to your destination. Likewise, if you are determined to fight back in this situation, Strafe > Sight > Burst > Unsight > Strafe > Resight > Burst > Unsight > Strafe. This will naturally alter your movement speed and make it hard for an enemy (Player or AI) to properly lead you. Being inconsistent in your movement is the key to surviving, ESPECIALLY against other commanders.
Note that against Players, it's tempting to Jump and boost, however most good players will be able to very easily lead you in the air, and you won't be able to alter your direction very well. So while short "Bunny Hops" are helpful, avoid getting any serious airtime in this situations. The AI is completely indifferent to tracking the player across all the axis. They are equally incompetent on X or Z.