Put your palms directly over your eyes. Block out all light without putting too much pressure on your eyelids. Try to see the color black. You may see other colors or images, but focus on the color black. Use a mental image to remember the color, i.e., black tar.
Continue this way for two to three minutes, thinking and focusing on black. Slowly open your eyes, gradually getting accustomed to the light. Experience the sense of relaxation in the muscles that control the opening and closing of your eyes.
Color imagery and eye relaxation can be done when you need a technique and don't have much time. They are fun and will keep relaxing interesting. Try to slip one into your regular activities every now and then.
(Thanks to the Lupus Foundation of New Hampshire for this interesting tip.)