While there are variations, the standard upper Hawley retainer consists of a labial bow, made from .032 wire, that crosses the occlusal plane, distal to the cuspids, and your choice of clasps. Clasps are used as anchorage and are placed on the first molars. The loops are for adjustment capabilities.
A very popular add-on are Lollipop Springs or O-Springs. These springs allow for torqueing, rotation, or tipping of teeth that require minor movement.