Assuming that the song is well-arranged in the first place, the most interesting parts of the song as well as the hook should jump right out. Sometimes that means wading through a lot of extra tracks and muting them to build the dynamics of the song. It all depends upon the song, the arrangement, the players, the recorded sound, the artist/band, etc. Sounds like a cop-out, but there are a lot of factors that go into it.
I much prefer that I start the mix without the artist/band, then they come in about 5 or 6 hours later and make their suggestions. Of course, if I've recorded the tracks myself, a lot of the mix may be already completed in the box way before the final mix, so it doesn't take that long to finish and the artist knows exactly how it will come out.