Using a reverse grip on your curls will use more forearm muscles and give you a better squeeze of the biceps at the top.
Stand upright and grasp a barbell with a shoulder width grip. Grip the barbell with a double over hand grip, or with your palms facing your body. This should be the opposite of your standard barbell curl. Squeeze your forearms and biceps as you begin to raise the bar up to your shoulders. Continue to curl the bar until the bar is at your shoulder height and your biceps are completely contracted. Hold this position briefly and then slowly lower the bar back to the starting position. Repeat this movement until you have completed your set.
Keep your elbows tight to your body and do not allow your upper arms to move during this movement. Make sure you feel a squeeze in your biceps at the top position. If you do not feel a squeeze, you are not bringing the bar up far enough.
This exercise can be performed with an EZ Curl Bar or dumbbells. An EZ Curl Bar will take some stress off of your wrists, but each individual will have their own preference.