I've developed a new techique for making large yarn paintings by adapting Kaffe Fasset's idea of making one's own space-dyed yarn by tying different yarns together. I choose a theme -- the sky, a summer garden, gather together about 100 different yarns that fit it, and then tie small pieces together and make large balls.
I find this to be really exciting work. By the time I've finished rolling up a ball, I've forgotten what's in the center, so every new piece of yarn is a surprise. I use the basic single crochet stitch, so the yarn, rather than the stitching, is the star.