I don't clam to be an expert but it really depends on the song, If you want to send me a sample you can to firstname.lastname@example.org and I will have a listen and tell you want I think. If I am making a song in classical/NIN style, which I usually do then I like the bass drum to punch through the mix for a very short period of time and then get the hell out of there and basically the same for the snare. But crash cymbals I love stereo samples of them, so I often just use my drum track as a guide and use stereo crash samples I have made; I love them to have long decays, attack loud and the fade into the mix. Hi-Hat I have always had a problem with, I never know wherther to have it at the front or back of the mix. Toms I have them at the front but pan them left to right with the highest tom on the left and the lowest on the right so tom rolls really go across the stero image. Well that's my input.
You know when you have put too much low end in when it sounds too bassy, simple as that.