+1 to what AT said.
Also, another increasingly common approach is to put a hi-pass filter just before the comp and then another EQ after for sculpting work. Since just about everything except bass and kick are hi-passed these days it can sometimes help to only have the compressor work on the "useful" stuff instead of having its headroom used up by bass frequencies that you're just going to get rid of anyway. Focusing EQ works great for that task btw.
Dean