I think the best motivation is to have another awesome lucid dream. So don't burn yourself out by doing RC's and things when you're already unmotivated. Just tell yourself you want to lucid dream again every now and then, then if you have a great one it should be all the motivation you need.

That's pretty much what happened to me. I got sick of trying and getting no results so I took a break but still reminded myself before bed of what I wanted. Now I keep getting short LD's and they keep motivating me because they're just tastes of what could be.