Practice practice practice.
I myself don't turn away from the microphone to breathe.
Make sure that when you talk or sing into a microphone that you don't move your head around too much, and that you direct all the sound into the microphone. An example of this is if you are playing guitar and singing at the same time, if you look down to see what your hands are doing, chances are your voice will stop going through the microphone so much and it will be harder to hear.
Project your voice outwards. I'm not quite sure how to explain it properly, but you don't really want it to sit back in your head or your mouth, you want it to go out and be heard. Singing louder to compensate for not projecting outwards is not a good idea, as far as I'm concerned, because if you're singing loud, but not projecting, its harder to get a varying range of emotion in your voice (at least this is what I've found).
Enjoy it. If you don't enjoy yourself, it will affect the sound.
Practice even more.
Play around with your voice. Put on crazy accents and the like. They don't necessarily have to sound good, but it will help you to get more sounds in your voice.
Note: Some of this advice may be useful, most probably won't. Just make sure you try lots of different things, to see what you can do with your voice. This isn't really tricks so much as tips, but meh.
EDIT: Oh, didn't notice the topic change. My bad.