What type of mic is it, and how are you recording with it?
Hitting the Phantom power isn't going to do anything to the level- you either need it or you don't. You need phantom power for condensors, but not for dynamic mics. Turning it on for a dynamic won't do much, but having it off for a condensor will mean that the mic won't be powered, hence it won't work.
You might also find that your problem lies in how you are using your mic- some of them have pretty rapid drop-offs etc.
As for how to record, if I'm not using a drum machine, then I try to do an "area record", where I get the entire band to play and record a mixed-down version of the song.
Then, I play that back to everyone as they play- giving them a reference. This will generally work (depending on the calibre of the musicians-heh). Then, I record each track individually, which gives a nice, "clean" sound.
I dunno- maybe this is a shite way to do it, but it seems to work for me...