Hi twinsufficient - my DTs are now 4, so the pain and horror of having a pair of two-year-olds is still sharp in my memory.
Be obsessively fair - work out a way of juggling both twins onto your lap at the same time (one per thigh works well for me). If they squabble over a toy, get a kitchen timer and set it for two minutes - tell them that when it beeps they have to swap. I used this from just before they were two and they took to it quite well - still use it as the squabbles sadly don't stop!
From two, we treated screaming for no reason with a trip to the time-out mat in the hallway (our hall is within eyeshot of the living room, also within earshot so they can hear all the nice games they are missing out on). Again, they cottoned on pretty quickly so all I needed to do after a while was hiss 'Time out?'.
Also, I shamelessly exploited the soothing powers of CBeebies to tame my two
. I kept it to maybe a half hour or so in the mornings (cup of coffee, flick through the paper) and an hour late afternoon (get the dinner on, quick tidy up). Because the TV wasn't constantly on, they looked forward to it and paid more attention (ie were nice and quiet) than if it had been on all day.
Best of luck. It really doesn't last for ever - my two are pretty much fully-functioning human beings now and much more pleasant to be around. Also, when things get really rough, concentrate on the lovely things they do. If you find it hard to think of any, keep a handy written list available!