Open up with a mortar volley then straight away concussion shot the silver/gold enemies. Clean up whats left, heal, let some cells recharge then tackle whats left. A good method is to send your companion onto the CC'ed mob and let it get some threat, then open up. This can buy you some time to DPS while you use some of your companion health up instead of your own. Another good strategy is to mortar strike then straight away hail of bolts or sticky grenade. Sticky grenade can scatter the weaker enemies if they are not killed by mortar strike and knock them down (possibly killing them) again buying you time to finish them off. Also, learn to kite the harder enemies as its invaluable later on, as some of those sith are terribly painful up close in melee, so even if you can shave off 1/3 of their health with hammer shot while kiting around, you can then stand and fight and not be at such a disadvantage. As others have said also, breaking line of sight with an enemy that is simply too tough can again buy you time to throw a quick heal on yourself and avoid some of their more nasty abillities. Theres really no "rotation" its more of a priority system, with the goal being to not blow your ammo too fast and cripple your recharge. Use the most damaging abillities first and weave in hammer shots to maintain that fast regeneration. If you can master this you can come out of fights with almost full ammo.