The best "trick" I can think of is to get things to sound how you want them to before you ever mic them up. When you're tracking, play dynamically to the mix in your headphones so that you wind up with a "faders up" mix before any adjustments or post processing. Make a safety copy of this mix to compare your processed mix to. Sometimes it doesn't need much at all, and sometimes it was better before you did anything to it.
Maybe I take for granted what I've learned playing live.... I guess I just know what a snare "ought" to sound in relation to a kick drum, and in turn to a bass... And how a rhythm section "ought" to sound in relation with the guitars. That's what I think of as mixing mostly, the dynamic relationships between the instruments and the silence.
Otherwise, I guess I'm looking at sounds themselves and getting them to sound right pre and post-processing. If I don't know how to do that, I'll want to learn how before I'll track a thing.
