1. Dilute isopropyl alcohol (not rubbing alcohol, as it may contain oil) into a solution of no greater than 50% alcohol and 50% with distilled water / deionized water. Purified / bottled water works well too.
2. Put the solution in a small atomizer bottle, the type that you push from the top to get a fine mist. Don't use this, however, to spray on the screen itself.
3. Apply the solution to a cotton cloth, such as an old T-shirt, lint-free microfiber cloth, or other very soft cloth. A large cloth is best, since it will help to reduce the risk of leaving streaks across the screen from finger pressure.
4. Wipe the cloth against the screen in a circular, or other consistent motion. Apply an even pressure to the cloth but take care not to press your fingers into the cloth or screen.