Yes, carrying a small/bigger notebook/sketchbook/playbook around and noting things down in it as they come to you, occur to you is the best way to tap into your own creative thinking and feeding it up.
Note it down. You won’t remember it all. Try to note down a thing a day. When you catch a glimpse of something unusual, or when you see something special in the ordinary…jot it down. In writing or in a sketch. Just a notebook and a pen/pencil is all you need to start with.
Recently an idea for my exhibition piece got born like this: I caught a glimpse of the shadows twigs were casting on the pavement. The intricate pattern, so I took out my notebook and traced them down…later I developed them into a Spring Shadows piece that made it into a local show.
When I go back and see what I had written/noticed previously, oftentimes I am surprised at how much there is…and see the patterns of interest too. What is it that you notice/see?
So your task for today or tomorrow is to get yourself a small notebook/sketchbook to carry around. Keep on you at all times. Try it. Note things down. Just for yourself. And see how your abilities to notice, to record and develop ideas, develop :-). They will. Promised. Guaranteed.