The computer and the internet have opened an entirely new spectrum of coloring and drawing. Adults now make very sizable livings creating, drawing and coloring pictures for computer animation including video games, movies, commercials and items most adults would never consider, such as some high-quality information websites. With this option available as a full-fledged career for adults, it is no wonder that the tools and formats used in this style of artwork have carried down to children, albeit on a smaller scale.
Coloring in pages that are specific for coloring. I have found a few websites that have pages to color that are downloadable. You can also try a resource store for teachers. These specific pages for coloring are pictures or drawings of a variety of design that you alone enjoy. You can make your own coloring book with these pages. After coloring the designs you can write your own narrative about how you feel. Write how the design itself and the colors you used relieved your stress. You can even write a short story about the design if you like, this is your project and it is for your eyes only.
Coloring in a Doodle Book. You can do this very effectively by getting an artists sketch pad. This is a pad of blank sheets of paper used by artists to plan their paintings or creative work on, much like a writers rough draft. Once you have your pad, take a pencil and start to doodle. Make lines, circles, shapes, what ever at the time makes you feel good. Then color in the spaces within the doodles. Even if you think you are not a very creative person you will feel productive and relaxed after a few doodle your noodle calming sessions.