Oh, I love my RCs. I never know, which one will show up in my dream.

1. Looking at hands and counting fingers.
This is a classic from Castaneda's book. It goes together with awareness question and classic mantra "next time I'm dreaming, I look at my hands and realize I'm dreaming. It got me lucid for first 30 LDs or so.

2. Thumb/palm - it's painfull now so I'm switching to new RCs

3. Levitation "If this was a dream, I would levitate"

4. Changing something "If this was a dream, that [thing] would be [different color...]

5. Nose pinch

Just remember, they will not work by themselves. You have to add awareness question "wow, am I dreaming?" and for a moment you believe, that you are. Then you examine your surroundings and do a couple of RCs. First RC is "looking at hands" and then whichever you like. You fully expect it to work (thumb going through your palm, levitating up, having different amount of fingers...). And you finish up with mantra "next time I'm dreaming, I look at my hands and realize I'm dreaming". This is just one way to RC - you can do it differently.