Keep you weapons clean. I am not necessarily talking about your guns although that is important. I speak specifically about your melee weapons, and ultimately I am talking about your blades.
Cleaning not only prolongs the use and effectiveness, but the hygiene factor is also just as important, especially with what appears to be a rampant zombie infection on the loose.
I cut myself with my own knife once, this was the same knife that I had used to kill zombies, my Gerber. Fortunately I keep all my weapons clean. Despite that I didn't get any sleep that night, the worry about infection strong in my mind, I had almost convinced myself twice that I was infected, but I wasn't and it didn't kill me.
So keep your weapons clean, because accidents do happen, and the life you save may be your own.