Exits. Kind of a simple term, when you think about it. Sounds neat when you roll it around on your tongue for a bit. Conjures up a few images, probably the first being those old signs that used to light the way to egress. But in a more practical sense, exits are fundamental to hunting zombies.
The first thing you should think of when you arrive anywhere is "How will I get out if things head south?" If you're entering a house, check and make sure the downstairs windows and doors are closed, but unlocked. You don't want anyone coming in after you, but you certainly don't want to be delayed if you have to bug out in a hurry.
For example. Duncan and I were charged with house clearing near the old school where we first set up a community. I headed in the first house and cleared the first floor, moved up to the second with Duncan behind me. At the top of the stairs we found a family of six waiting for us, four of them teenagers and faster than normal. As we bolted down the stairs to gain some room, we found a trio of zombies from the outside had come in the front door to see where we had vanished to. We didn't have the time to kill the ones on the ground before the ones on the second floor were attacking from the rear.
Duncan actually used his head for a change and dove under the ktchen table, standing up with it on his head, and charging the group by the door. The table knocked over the zombies and the two of us used the platform as a bridge to get the hell out of there just as the family came tumbling down the stairs.
From that episode, we learned to have an exit always, whether it be a rope out a window, a busted door, anything. When the Upheaval was still new, it was interesting to see how well trained we had all been. Most people were reluctant to break a window, simple because they never would in their former lives. it was a taboo we had to get over in a hurry. John always said the big patio doors were the most fun, but it let the zombies out, too.
Always know how to go back the way you came, and chalk the damn walls if you have to. Office buildings are a pain to clear, we typically just set them on fire. But they have nice central stairs which work really well as exits or funnels. Get a group to follw you up the stairs, then set up a killing zone on the roof. One at a time and your targets come to you.
Always know where the exits are. If you aren't sure, don't go in there. You'd be amazed at how much trouble you can avoid by simply walking around the building.