I got this idea because since I sketch to come up with ideas for paintings, I wanted to do something that could be translated more easily to a painting.
Using shapes and colors instead of lines, you’re already using the “language” of painting. This is a really simple technique that anyone can do.
All you need are paint samples (get as many as you can from a hardware store-they’re free), scissors, a gluestick, and your sketchbook.
Look at the colors you like together. Be experimental. Work fairly quickly. Don’t worry too much about the results. When you sketch this way, you’re only working with shape & color, allowing for unexpected results.
Cut shapes out…. glue them down… repeat. Do as many pages of this as you can.
Instead of tossing out the smaller scraps, use them to add detail to your collage.
Use these sketches as references for paintings or designs later on- this way, you’ll arrive at different ideas than if you were using a drawings or photographs.
Of course, this technique can be combined with drawing to add interesting variation & detail! Feel free to experiment, of course.
Oh, and obviously you’re not limited to using paint samples- I also used construction paper and a cut up shopping bag. Seriously, use what you have. It’s the best way to work. I set aside brown paper bags, wrapping paper, old life drawing newsprint, etc. that I always use in collages. Have fun!