Most of the guys here know this, but for newbies like me.... Often on the web, you'll see advice to get your individual channels to peak at -6 to -3 db, and then mix for -3 to 0 db. However, as pointed out at http://www.fxpansion1.com/mixing_with_bfd.pdf and probably elsewhere, you lose a lot of clarity and definition that way. It takes more restraint, but it's much better to peak individual channels at only -12 to -15 db - ie, the faders are LOW... and also, none of the faders should be higher than the master level fader (or at least, not too many faders, and not for very long). As pointed out, you can always boost the level of the final mixdown track itself. But allowing yourself this vast clean headroom (one of the advantages of digital over tape analog) will make things sound incredibly better....kind of like replacing a set of rusty strings (I'm not kidding!).