Ok, just had my second lucid dream a little while ago and this method worked for me. I remembered reading somewhere that to improve visualizations, one technique is to focus on a candle flame. While in my dream, I noticed I didn't have very much control and I decided to attempt this while in the dream. My control and clarity increased immensely.

Candle Focus Technique
First things first, become lucid. When you become lucid, take a few moments to take in your surroundings. Relax and don't become too excited. Then look around for a candle. I'll bet there's one on that table right behind you. Approach the candle. Take about 10 seconds just to look at the candle. See how it flickers and appreciate its beauty and wide range of colors. Then take another 10 seconds or so to feel its heat. Pass your hand through it quickly a few times. And then take a final 10 seconds to realize how your surroundings are only a part of your mind, and that the candle flame you just perceived, is as well. Realize that since your mind can create such realistic sensations subconsciously, you can do the same consciously.

I hope this helps, I've only tried it once and I've added some more ideas and embellished my original concept, so I don't know how consistently it works. Please let me know if it works for you, or if you have anything else to add.

-Out of the Blue