Wrist Strengthening Forearm/ Wrist Strengthening Excercises?

Forearm/ wrist strengthening excercises? - wrist strengthening

I usually play great tennis and other sports, rowing, but i slowed down in the. I would like some ideas and links to strengthen the wrist and forearm exercises. I need to get stronger for the spring meeting of the tennis and paddle. The problem is that I only dumbbells, stress balls, and rubber bands. Very basic things.

Thank you!