I have the two bottom bars and the right bar active. I put stuff I dont use as often (quick travel, recuperate, buffs etc) on right bar. On my main bar I map them 1, 2, 3, 4, Q, E, R, T, C, V then the last two buttons are the default - and =. I have the second bar set up the same except add a CTRL in front of the other bindings. Take all your cover abilities off the bar you use when not in cover (obviously) then go into cover and set up that bar with whatever you seem to use most during cover fights. For the second bar I put skills I use whether in or out of cover, like the interrupt enemy ability, the recover energy instantly, disable droid etc (I'm terrible at remembering skill names). It all seems to work well for me so far at lvl 24.