One of the most important scuba diving skills to refine, particularly for those who want to transition into technical diving in wrecks and caves, is reel and guideline use.
This video explains and demonstrates some of the basic points about how to use a reel and guideline. In addition to use in overhead environments, reel skills can be also be useful to any diver as a tool in navigation, mapping and deploying various buoyant devices. A good place to start is learning how to do various wrap's and tie off's, many of which are demonstrated and broken down in this video. With a bit of practice they will quickly become second nature.