I have several ways. Listening to music, reading, sitting on my patio meditating.
Reading is my choice of relaxing. Actually, cooking is too.
Reading, watching an old movie.
My ADD is a serious obstacle to formal meditation, but I do attempt to practice some informal mindfulness practices. This entails intentionally focussing on something, literally anything, occurring in the present moment. It can be just being aware of my breathing or taking in some sound, smell, or sight in nature. It works so long as I can banish any ruminating on past or future.
Music, sitting outside, fishing, watching a movie.
Painting relaxes me more than anything.