Allowing your mind to focus on nothing is good, but focusing your mind on something entirely new can stimulate it to work in different ways. Forcing yourself to think creatively in a way you normally don’t can spark new ideas.
For example, if you write all the time, doodling helps you imagine what things look like, instead of feel like. If you’re a photographer, sculpting forces you to think about a subject three-dimensionally. If you’re looking for a visual hobby, the Galaxy Tab S7 is a great tool for digital colouring books and a good place to start.