Creative Brainstorming consists of writing down all the ideas you can think of in a moment. The goal is to exercise the "idea muscle" to promote creativity and mental sharpness.
A journal to keep track of your ideas
With a pen and paper, write down 10 ideas. It doesn't matter the theme, nor the quality. Focus on writing down 10 ideas no matter what they are.
The goal is to exercise your mind. Ideally, write them down in a journal, so you can check them out in the future. You never know, you might come up with some very good ideas that you can implement!
Find the best time for you according to your routine