A few ideas are:
Doodle with your art materials and mediums. Play around to see how they work, try them out on different surfaces.
Take a line for a walk. Paul Klee would let his pencil or brush wander on the page wherever his hand took it, creating an abstract line design. After he was done he would decide what it looked like. I learned this about Paul Klee at the Minneapolis Institute of Art as part of their Art Adventures program.
Draw or paint lines to music.( A personal favorite) See the previous post for more information.
Blind contour line drawings. (Another favorite & I hope to do a video demo to help make it more clear). Choose something to draw. A lot of wrinkles or folds is best. Look at the object. Follow the lines with your eyes, draw them with your hand, never lifting the pencil from the paper so that you draw one continuous line going back and forth through the folds, and never looking at the paper. It will most likely not look like the object when you are done. It isn't supposed to. It's an exercise to help you see what you are drawing.
Another warm-up idea my high school art teacher had us do everyday was to illustrate a quote she would write on the board.
Some students find the above types of warm-ups a little frustrating and prefer something a little more traditional like the warm-up worksheet I made and use for students who prefer it. The idea is to copy what is in a box in the box below it. Empty boxes can be used to come up with a new idea. Feel free to download and print your own here.
