The brachialis is the often-overlooked muscle between the biceps and triceps. Training your brachialis is a great way to help "project" a massive arm. Why? Because as the brachialis develops, it pushes your biceps and triceps further away from one another, making for a wider-appearing arm.
The standard hammer-grip curl is good, but I prefer the cross-body variation shown here. Grip the dumbbell as hard as you can throughout the rep.
So you think you know how to do plain, simple, Incline Dumbbell Curls, huh? Well maybe you do, but there are at least a couple of trick you can pull to make the movement a whole lot more effective.