Only very recently started working my top game, and have to say I'm very pleased with the result, though i'm a little bigger than most at class so that probably helps a lot.. neways - sure youll get some better responses but this is a good start:
side control - i like both knees up side control, if you are flexible enough to keep your hips low, id say use it.
get one knee in their hip, and the other knee deep slightly under their shoulder towards the head if you can, you can block the hip on the other side with your arm if you need to, and you can keep the top half of their body down easily by going to a gable grip crossface whilst keeping chest pressure down on them. -> i used to not be able to keep side control at all until I asked my instructor and now I find myself pretty strong here. Little details.
Not sure what you mean by killing the arm, but if they have their arm inside when yo have side control, you can clear it by keeping chest pressure down on them, switching your hips across and using your knee to clear the arm, then switch your hips back so yoru leg comes back into a control position with their arm now 'out'. (not really sure if that'll make sense, again, i had to be shown this.)
If they manage to get an underhook on you whilst you're passing/have jsut passed, immediately hop up to knee on belly, as the underhook'll be what they use to escape. go to knee on belly, put pressure down, then recollect your underhook as you settle back to the crossface.
If you are tryina pas the half guard, fight for the underhook and use your head/shoulder under their chin to push them back flat so you can work the pass.
Also, use your chest when dominating a position / starting off subs. consciously push down and push your chest into them.
Sall I got off the top of my head
hope it helps a bit.