I think redriver is totally right about goalsetting. I found that rubbing my hands together has been more effective than spinning. Also I think it would help if you try and let go of those past failures (which far easier said than done). People come back after months off from attempting to LD because of those failures to find that it was not so difficult. And once you jump over that first major hurdle you'll be doing great. For me, getting rid of the word "try" does wonders.

You will have a true lucid dream tonight. It will be awesome and you will never doubt your own powers again.

Let me know how it goes