I tend to jot down moments, lines, interactions that don't really make any sense. I try and explain these scattered notes to my close friends, and they become more and more logical. I see screenwriting as a bit like a math equation which I have to solve.
Sometimes if you want to see a change for the better, you have to take things into your own hands.
I think if you're a competent actor with a good imagination, and if it's on the page, it makes your job a lot easier.