Chest Supported Incline Bench Curls
Doing a lot with a little. Ive bicep curled 150lbs - that's called ego lifting. This exercise is actually how mountains are built.
Taking your legs out of the equation keeps you from using your body momentum. Leaning against the bench pad keeps your body still and forces the lift to be focused on The Biceps!
Like I've said before, full range of motion. Try flexing your tricep at the bottom of the exercise and bringing your pinkys to your ears - twisting your palms through the rep.