One of the things that strikes me as odd about voice overs is the tendency to make unwanted noises from your mouth. It could be clicking, or smacking and it is all annoying to me. In normal conversation I don't think people hear it but with my recording gear on, I hear everything. In an effort to remedy this, I do my best to keep my mouth clean and moist so I can provide a clear and concise read. After a few hours it's not as simple as it seems.
The key to a successful voice over is to keep your mouth moist; water for me has the best result but too much and I end up in the bathroom too many times. 5Gum RPM Mint has been been the fix for me. It goes in and out of my mouth all day long. Don't get me wrong I like diet soda too, but soda has another side effect that can be pretty funny to my kids when they hear a recording of me burping. Yep, mom is pretty cool!