yeah, I have read about looking at my hands from time to time. And if it is a dream, my hands will be funny looking, may have more than 5 fingers or may be blurry.
Sadly, I forget to apply this technique, when I am dreaming. I am affirming something like,
"I will remember to look at my hands when I am dreaming and become lucid."
So far far, I have been forgetting to do so. I will keep trying.