To-do lists didn't work for me for a while, but I eventually figured out the secret for me. I kept dropping off on my usage, forgetting to write down my to-do's. They usually only worked when I was feeling motivated/inspired, not on a daily basis.

I found that the secret for me was To-do's in a spiral bound notebook, so that my list was always staring me in the face and begging to be added to / crossed off. The physical act of writing and crossing off helps tremendously.