When I sing or speak into a mic, I hold it in what I call the Cindy Crawford Mole Position. Why? Three reasons:
1) It avoids mic pops: The puffs of air from the letters P and B (and T and C to a lesser extent) that pops the microphone in an ugly manner (even at quite a distance).
2) To get a good mix of nose in the sound, to avoid the slightly blocked nose sound you get when there's not enough Ms, Ns and NGs.
3) So the audience can see my mouth.
Yes, moving the mic to one side a little (somewhere around the corner of the mouth), angled in (aiming diagonally back towards the lips) and slightly up, will solve all these problems: The pops can go past, nasal component is added and you can see the mouth... yay! What's more, when you sing louder, try moving the mic around your face a little rather than away: This means the warmth (low frequencies) aren't lost as you get louder. This is easy if the mic is on a stand... just turn your head away from the mic.
People often complain they sound weird through a mic and this is mostly because you naturally hear yourself through your head (via the estacean tubes, etc.), so the nasal component of your voice is an important part of you sounding like yourself.
Now, getting singers (and speakers) to do this is a challenge, as we're all obsessed with symmetricality. But several renowned audio engineers I know have confirmed that most people don't sing symmetrically anyway. And if you play an asymmetrical instrument (like guitar, bass, drum kit, accordian, hurdy gurdy, etc), it's not going to seem strange to the audience. Most piano players mic the voice from the side anyway. And if you're holding the mic in one hand, as most singers do (well, except Chrissy Amphlett), it's more comfy to have it to one side.
So, give it a go!
Challenge convention... just because people have been eating mics for as long as mics have been around, doesn't mean it's the right thing to do.
Extra note: The chin position is OK for speakers and comedians, because at that distance, the mouth/nose mix is fine, but because of the distance, the mic has to be turned up louder and thus it's no good for band situations. And unfortunately, many people let it drift up into the pop zone (which is lower than you might think), and that's extra bad, due to the fact the level is pumped up and the EQ is made bassier to counteract the distance... aarrgghh, pop-o-rama! People just have to get over the symmetry thing, as the sound doesn't care. An off centre chin position (like, in jowl position), is ideal for speaking gigs, as it still leaves the mouth visible to all, but let's you bring it a up closer without the risk of popping.
Here we see renowned Auckland vocalist (and teacher of many) Caitlin Smith having only recently learnt the joy of the CCMP.