Start in the dead-hang pull-up position. Instead of pulling straight up, pull to your left side, touching the top of your left pectoral to the bar. Descend under control, then do the same thing to the right.
You can also go side-to-side for two reps before descending: pull to the left, hold at the top, transition to the right, then lower yourself. Start the next rep by pulling to your right.
Dan John is Testosterone's Yoda, wise as hell but with better skin and a heckuva' lot higher PR in the snatch than the original. However, our Yoda has had his share of Yodas to learn from. Read here as he shares his most valuable weight-lifting lessons.