The best time to do your repotting is in spring. Why not take the opportunity and update your flowerpots as well! The paint stamp for this purpose can be anything: few pieces of rolled toilet paper or a carrot. Also, paint can be almost anything: acrylic paint is the best, but e.g., makeup is a sort of paint too. If you use lipstick as paint, you can use your lips as a paint stamp.
Stamp the pot and put the flower back.
Materials: paint stamp, paint, a flowerpot