1. Instead of holding the dumbbell in the middle of the handle, hold it near the top in an offset grip. That way, when you curl the weight up you'll increase the resistance and tension at the top.
  2. For hammer curls, start with the dumbbells on the front of the legs. This gets rid of the wasted range of motion and increases the continuous tension ¬– an important part of hypertrophy training.

Related:  The Complete Guide to Big Biceps & Triceps

Related:  10 More Biceps Training Tips