First round... fan out your troops as shown, then end your turn. Last night I started using two of my turns and blasting little crenelations into the side walls and putting my troops in them. (like the chunk missing out of the wall in the top left corner of the pic)
Once you have your soldiers in place, have someone blow the front door off (takes 2 laser rifle hits)
This is usually the end result...

Mix it up with stun grenades, flame/chem guns, and you've got a camping tactic that'll keep your soldiers alive and even promoted.
I have yet to try this on the next tier of aliens. It'll be interesting to see if it works on Destroyers, they'll probably come in and have their way with me. [:(]