I've personally had success with starting small and simple. I pick a habit that promises improvements and do one small and simple thing every day related to it. As it becomes a habit I can see results and adjust accordingly.

The best habit I have formed is to see the benefits of actions and forcing me every day to do them (by starting small and simple).

Its not a race. It takes time. Sometimes years. Be kind to yourself. You will make mistakes. Identify the mistake and learn from it. Then move on.