I find the best way of honing the skills is to fly with someone else (who knows what they are on about!) whenever possible. Most people will not fly as accurately or perform to their best when solo.
At your stage I wouldn't get too involved with the mountains but under-flung toads are good for building on the basics of hover skills and thinking about power restrictions. I enjoyed some competition flying for a while and, as the previous poster says, these exercises also help the basics. Accurate position and time keeping for navigation, ground cushion work and advanced transitions flown as well as you can can't hurt. With the latter keep at the confined area exercises as well. Try to get someone else (an instructor) to give you exercises that can be tried in your local area. If your area is the NW give me a call!!
Good luck
Dai (A2 retired)