Parallel distortion is an excellent way to get unique and interesting tones out of our synths. Often, our synths sound dry when unprocessed, but when we add distortion directly onto them it sounds muddy and bloated. Using parallel distortion, we can get the best of both worlds, keeping the clarity of our original sound while adding subtle tones of distortion.
The easiest way to do this is to duplicate a channel, add distortion, bring the volume fader all the way down, and then slowly mix it in. Alone, the distortion may (should) sound excessive, but when mixed against the clean original synth it will add warmth and depth to the sound.
Not only can we use this on synths, but nearly anything else in our tracks, such as drums, vocals, and bass. Play around with different processing chains on the parallel tracks, using different distortion effects and post processing (i.e. EQ, reverb, compression).