[*]Second up: Be aggressive! Take advantage of stealth to set up (overwatch) ambushes--trigger it with a grenade or squadsight sniper for maximum effect. Done right, this can eliminate a pod or maybe even two. It also helps outrun timers, but they're less of an issue in WotC.
i strongly disagree with that.
overwatch ambushes are actually a trash tactic and here is why: everyone shoots random targets with no guarantee to kill anybody.
what you need to do is to think how you can maximize the damage to the pod with the opening attack (grenade to shred armor, preemptive shrapnel with reaper combo etc).
after they run to cover, you either flank them with carefully placed soldiers or just blow up the cover of the most powerful enemy and wipe it out. rest of the pod should be little of challenge, you'll suffer like 1-2 attacks at most.
if you do overwatch ambush, you opt yourself to be left with full living pod (its xcom baby) and they get following turn to flank the shit out of you.
you have to dictate the battlefield flow, not rely on chance