H2oskiphil
It needs more cowbell!
and the right amount of dynamic range changes (if the singer moves around - something that's never been covered in any thread here, but is very important).
OK...you went there....
How DO you handle a singer that moves all over the place? I've got one in the studio now that has a TON of range, and the dynamics in the songs require everything from just over a whisper to full-blown, from-the-gut blasting. He knows enough to back off the mic when he's letting it rip, but he also moves around (left to right) when he's not at either extreme, and does a lot of movement towards and away from the mic when he's "into" the song, regardless of the dynamics of the song at the time he's singing.
Since my room isn't the greatest, I've tried to keep him fairly close to the mic, but it's like trying to put a collar on a butterfly....we've had to re-do a few vocals because he rolled into the mic during a particularly dynamic part of the song, and I wasn't quick enough on the fader....