Also get rid of frequacies you dont need on cetain parts. For example - Put a complete cut on all freqs above 500hz on your bass, and then take this down as far as possible without changing the sound. Do this with most of your stuff because if you have just small amounts of a certain freq on individual tracks, it soon adds up. Be carefull not to lose your harmonics on synthlines and basses as you may lose warmth for clarity...