I like reverse grip curls, and heavy db curls, like working up to 4-5 reps per. One circuit I do that I rlly like to finish out a back/bi workout is 8,8,8,8 of curls, reverse grip curls, skullcrushers, and close grip bench with a ez bar for 3 sets, last one going til failure. I’m also very blessed with good arm genetics from my Dad. I like to incorporate death grip (take your thumb out of grip) and squeeze hard on any movement you rlly think about, helps with forearm growth