One thing you have to remember: if you control less than 50% of the command posts, your reinforcements start draining away (your team's ticket count bar starts flashing and the announcer says "We're losing reinforcements!"). Conversely, if you control more than 50% of the command posts, the other side's reinforcements start draining away. So make sure you capture the nearest enemy command post as quickly as you can, and hold it. And if the other side gets one of your command posts (usually someone on a speeder bike takes one of your rear command posts) take it back immediately. Don't worry about capturing all of the command posts, just capture and hold 50% + 1 and the other side will drain away.
For fun on Endor, I play as a Rebel Pilot and run towards the Barracks (where the AT-STs spawn). Avoid combat, just run as fast as you can; switch your alternate fire to Dispense Health and Ammo and if you get wounded, just Alt-fire and you'll toss Health in front of you as you are running, you can heal yourself without stopping. Circle around to the right of the command post so you aren't seen. Look where the AT-STs are spawning, and sneak around to the tree nearest the spawn point and hide behind it. Only kill enemies that discover you, and avoid the turret that is usually manned. When an AT-ST spawns, run up and enter it. Kill all enemies in the command post, starting with the turret (blow it up so no one else can use it). Then you can either hop out and convert the command post (if you are brave), or just camp the spawn points and kill them as they spawn. It is important to face the AT-ST spawn point, and kill all enemies before they can board the AT-STs. That way you keep yourself alive AND you deny the enemy their AT-STs.