Object that helps induce LD's.

Does anyone have an object that can help them induce Lucid dreaming? Not necessarily an actually object, but even a sort of "Dream sign" type thing. For instance, I think I had a dream that involved a simple Mahogany chair. (I say think because I really don't know, it was just in my mind and was able to link it to a dream), and one night when I was trying to enter SP and had no luck, I decided to think about the chair. I just saw it in an empty space (That's where I remember seeing it) and as I thought about rotating around it I got very strong vibrations and almost entered SP. I probably would have, but I thought it was a bit weird. I'm not sure how to explain it, but the chair just seemed to be a sort of tool to induce LD's/SP. Anyone else have something like this? I don't think it's as simple as a dream sign.