There's the Drop: Complex Bass Lines Tutorial from Paul Crossman

By now, it's hard to escape the mind-warping sounds of complex dubstep bass lines that seem to bounce all over the place. In this tutorial, Point Blank instructor Paul Crossman looks at how to sequence the multiple parts that make up a complex bass line in Ableton Live. Definitely reminds us of Skrillex's "First of the Year (Equinox)":