Know thy screen

Find out if your phone's screen features a soil-resistant coating. If so, use a dry clean cloth to clean. Otherwise, use " a slightly dampened microfiber or lens-cleaning cloth." Avoid soaps and cleansers.
-Get in the crevices. Treat handhelds as you would a computer keyboard. Remove dirt using either a can of compressed air or a small brush "like a baby's toothbrush" If keys remain sticky, try a remoistened electronics-cleaning wipe and work into crevices with a fingernail or a toothpick.