Curling??? NOPE Wrong!
Do more heavy squats and deadlifts!
Yes, I know this sounds crazy since squats and deadlifts don't directly work your arms (except for the grip and forearm strength needed to deadlift heavy weights)... but it's true that regularly performing heavy squats and deadlifts can indirectly help to make your arms bigger and stronger.
The reason is that heavy squatting and/or deadlifting forces the body to release muscle building hormones such as testosterone and growth hormone depending on the resistance level, rep range, rest period, etc.
Generally, heavy weights, lower reps, and longer rest periods stimulate testosterone release, whereas moderate weights, higher rep ranges, and shorter rest periods help to stimulate Growth Hormone release. Therefore, combining both styles of training into your routines on either different days of the week or different cycles, can help to maximize both of these important muscle building hormones.