This tip actually applies to almost any DAW software (Digital Performer, Logic, Nuendo, and so forth) and even many samplers. Keyboard players have long layered a synth pad or even sampled strings under a piano track to add a little more richness. The problem was creating the right ADSR envelope for the pad so it didn't muddy up the piano. The fix today is easy. All you have to do is give the pad sound a slow attack (but not too slow) and then nudge that track just a tiny bit backward in time so that the piano's attack is clearly heard before the pad comes in. Some samplers like the Kuzweil K-Series allowed programmers to add a slight delay to the pad sound and Synthogy's Ivory includes several different pad waveforms that can be added to any of the three sampled pianos. Works great on electric piano tracks, too!