Larger arms sometimes accompany a busty shape. The best way to combat this is by wearing shirts with sleeves -- either three-quarter length or long sleeves will do. For short-sleeved numbers, try a cap sleeve. This will minimize the meatiness of your arms and make your body look more proportioned.
Try not to wear too much arm jewelry, as your upper arms will look even bigger with many adornments at the wrist. Stick with one or two chunky pieces at a time and keep fine jewelry at a medium size; too small and your arms will look bigger.