RC can fail to give results. It is easy enough to dream that your hands look normal and have 5 fingers each. Try also examining how you feel and such, which is called a mental RC. A simple one is that when you do your RC like examining your hands, also try to remember how you got where you are. Often the clue that brings lucidity is the realization that nothing makes sense when you try to think about things, like how did I get here, or what did I do a few hours ago.