Well, this is just an idea I was gonna try at some point:

Visualize yourself waking up after having lucid dreams and saying something like, "Yes! I did it! I had 3 lucid dreams in a row! I can have lucid dreams at will now!"

My thinking with this one is more about really feeling the joy of success and accomplishment, and therefore convincing your subconscious that you're already an expert at lucid dreaming. So you can just expect to have lucid dreams, rather than try to have them.

Hope that helps. Lemme know if it works.