I thought it would be kinda neat if we could all share our tips and tricks on making barricades or forts. Here are mine.
I like to always have a backup plan for my barricades, so I usually do something like this, if there is enough time. I use a small or weak item for making the barricade, a piece of fence works best, but I believe the plywood will work too if you can stand it up. I will take the fence pieces and make several layers of them protecting the entrance of the barricade. But before that I'll stockpile weapons and food for when I need it. Then I take a shopping cart and place it directly on front of the barricade, but facing it. I will explain its use later. I then take several propane tanks (small or large), and place them around the area of the barricade, but you don't want them too close because if they blow up, your barricade will be destroyed. If you have enough propane tanks and can place them so that their blast radii (plural "radius" overlap, you can create a very effective zombie trap. The most important thing to do with the propane tanks is to make sure you can get a clear shot at them, as you will need to shoot one with a gun to set off the trap. When shot, the resulting explosion will be devastating if you overlapped their blast radii. All the zombies in the area will be dead. While very effective, this method will only work once of course, so only use it when you're getting overrun with zombies. Now, the shopping cart. The shopping cart is there both as a zombie defense mechanism, and an escape route. If you need to get out of your barricade very fast, go behind the shopping cart, press B so you are holding onto it, then press A. Frank will kick the cart, sending it flying forward and creating a hole in the barricade (this only works if you used a "light" item to make the barricade, like a piece of fence). To use the shopping cart as a defense mechanism, simply do the same thing to it when zombies start to get into your barricade.