Yeah, I agree with Barbizzle on that. I suggest that you to relax and stay completely still until you're POSITIVE that your body is asleep and you're dreaming. When doing a WILD (Wake-Induced Lucid Dream, the technique you are using), it will be "blatantly" obvious when your body falls asleep. You will feel this sudden surge of energy (for lack of better words) rush through you and feel like you are falling through your bed when consciously making the transition from wakefulness to asleep. When you move before or during this process, it seems that you're letting you body know that you're not asleep. So I suggest you wait until you experience these sensation first before you try to move your dream body.
I don't know why people are always talking about rushing into a dream scene, I think that makes one more likely to awaken themselves if they're not fully asleep.