Try doing some EQing on the individual Tracks to prevent sounds from fighting over the spotlight. This is especially important when considering what is the thing that you want the listeners to hear the most. The mid ranges can be susceptible especially because many instruments will share that range. Also make sure you cut out unnecessary ranges for instruments which are not meant to play those pitches. (i.e Low-pass a bass type track, because you won't need the higher frequencies that I can produce because a lead will do that for you.)