Grip the inner bend of the bar so your hands sit close together, just inside shoulder width, with your palms facing up. Curl the bar toward your shoulders while keeping your elbows tucked close to your ribs — the narrower grip naturally wants to pull your elbows out to the sides, so resist that. The angled grips of the bar let your wrists sit in a more natural position than a straight bar would at this width. Squeeze at the top before lowering under control. The close grip shifts more of the work onto the inner, long head of your biceps compared to a shoulder-width grip, so expect the top of the curl to feel harder to finish.