Today is National Brush Day! The day comes after Halloween for a reason. Normally (in years without COVID-19), there is a lot of candy consumed. It makes sense to encourage teeth brushing after such a day.
As you think of composing your photo today, there are many ways to approach it. You can use leading lines using the brush or the paste, you can take a macro and get in close with the details, you can take a portrait of yourself brushing your teeth, or even another person in the act of brushing.
If the prompt doesn't speak to you, think of other brushes you can use. Hair Brush, Pet Brush, Pastry Brush.... approach the prompt in the way that works for you.