Drop sets is one of my favorite techniques for building muscle mass. Traditionally, drop sets are used on the very last one, or two sets of a workout, but you can get a whole workout of drop sets in using this approach.
Warning: you will feel an insane pump all the way through!
You can use this technique for any muscle group, and any exercise. I recommend starting with a weight that you would normally use for ten repetitions and drop down to a 50% (or close to it) of that weight. This should set you up for 3-4 sets of 6-8 reps with room to super set an assisting muscle group at the end (optional). Obviously, the weight and reps can be tweaked in order to suit your own training regime.