Fourth day in I had 2 LD's. That was the first time I did WBTB. First one was the best so far - I had full control of the scene, I changed it in moment without even using doors or anything. Second - I had no control whatsoever, I was only lucid. But it was still very enjoyable.
In first I became lucid without RC or dream signs, I just randomly thought "wow, I'm dreaming". And in the second one feeling of falling down (I was riding roller coaster) triggered lucidity, I guess it can be considered as a dream sign? Inner feeling?