The trick is to not rely too much on the same team early on. It's always tempting to keep using your "super squad" of elite troops on every mission, but if a few of them get injured in a normal fire fight, you may find yourself facing a terror mission with a half rookie team which can mean a total wipe or abort. Best to keep rotating troops through, leveling squaddies up until you have at least enough in reserve to field a whole squad. Abductions are best for this since you're not on any kind of clock, there's no worry about civilians and the maps tend to be fairly forgiving.
Right now I'm churning through recruits to try and get myself a full squad of psychics all levelled up and ready to go before I start the endgame mission....and just for fun and because it'll take a while to accumulate enough elerium to build all the psi armour I'll need anyway, I'm making it an all female team. For some reason, I'm having difficulty finding assault troops with psi ability. Only have one so far and only just got my second psi sniper. No shortage of supports though for some strange reason. Way more than I could ever use in fact.