OK, this is the first thing I actually did with my newly-created account. I've beaten Last Stand 2 plenty of times, and this is how I did it:
When in town, don't rush to get to the end, take your time and search all of the buildings, unless you're getting desperate (Last day almost reached, low barricade HP and not enough time to repair, etc.) then you move on. Survivors should be well equipped; with you having the best of the weapons. ALWAYS have a chainsaw handy, as if the enemy gets too close to your barricade you can mow them down and live to shoot another day or two. When repairing the barricade (which you MUST do every day) do the math. If you have 75/80 HP for your barricade and 5 pts are repaired each hour, do it once. Search the buildings with the gun icon first, then the ones with other icons (such as a church) then the ones with specific names. Houses are where I find most of my survivors. Don't worry about people dying while on search parties, it doesn't happen often. Try to get to the places with the highest population, because that means bigger city/more guns. YET there is a risk to this method, or madness should I say, as more population also means more zombies. If you don't want to go with my whole chainsaw tactic, at least have a high powered close ranged weapon on hand, two long range or two short ranged weapons are not right. Fat zombies have a lot of health, and look out for the zombies with body armor, should you encounter one, aim for the head (except for the soldiers who have helmets unless you're a good aim like me ;) ) or the legs. Dogs and running zombies need to be taken out first.
And remember: Aim for the head.