...Write It Down!
1) Do you want increase your productivity? Write It Down. Think on paper and consider your top concerns, assumptions, questions, goals, projects, and tasks.
2) Do you want to increase your creativity? Write It Down. Record your observations, conversations, ideas, insights, answers, solutions, crazy thoughts, and wild memes.
Simple advise? Yes. Easy? No! Think of all the times you had a million dollar idea for a great book, movie, business, or project but could not recall the details later.
I do suggest keeping a daily journal as a life enhancing habit. Why? It is an excellent way to insure that you capture your thoughts on a regular and semi-systematic basis.