(1.) SLOW DOWN!
(2.) Getting hits is more important than pure speed. Under competitive conditions, even if you are not consciously trying to go fast, you will probably go faster than you do in practice, so downshift about half a gear, control the trigger, watch the front sight, and get your hit.
(3.) When engaging multiple targets, the best method is probably to LOOK at the target you're about to engage and then move the gun and SHOOT that target. If you try to move your eyes and your gun mount all at once, you will probably over-run the target and pull a shot to the side.
(4.) DON'T CROWD YOUR COVER! If the configuration of the cover allows it, back off about arm's length. You expose less of your body to hostile fire that way, and it gives you more flexibility in engaging multiple targets from a cover position.
(5.) Practice shooting with strong hand only and weak hand only.
(6.) Consider practicing using your weak hand with support, aka shooting bilaterally or "mirror image". Depending on the configuration of cover and the position of the target in relation to that cover, this may be the best way to get hits on target without exposing too much of yourself to incoming fire.
(I'm a police officer who shoots PPC, IPSC and IDPA and so my frame of reference is defensive shooting more than pure compeition shooting)
You can only learn from experience if you pay attention!