Having a little trouble making your drums punchy and distinct? Are your keys a little bit flat and hidden in the mix? At this point you might consider reaching for a compressor or pushing the levels a bit but wait… there is an alternative.
Try placing an overdrive distortion on the sounds. Compressors can squash harmonics and severely alter the character of a sound (which is sometimes exactly what you want) but they are more useful for tightening up sounds and gluing together a mix with light threshold and ratio settings. Overdrive distortion, on the other hand, boosts the harmonic content of a sound adding grit and punch without (when used discretely) destroying its character in the mix.
For kicks and snares, using the native Overdrive plugin in Logic 9, I tend to set the boost to between 1 and 5 dB, keeping the output at 0dB (or less) depending on the level of the original sound. You can have an experiment with the cutoff frequency, though I find that setting it to 20000Hz (full frequency) is most effective in most cases.
For keys, you might want to push the settings harder (or lesser) depending on whether you’re looking for a vintage feel or a lighter sheen.
An alternative approach is to set the overdrive up on a buss or auxiliary send. If you do this you will be able to parallel distort it and mix the wet signal with the dry sound thereby getting the best of both worlds.
Just remember, you can have too much of a good thing. Overly heavy overdrive distortion will turn your pure and beautiful sounds into stomach-churning growls of death that swamp a mix and render all the subtleties of your mix inaudible.