Prevent damage to the monitor: Make sure there are no obstructions (paper clips, pens or pencils, cats, motorcycles, etc.) on your keyboard when you are shutting the lid.
Use an old clean toothbrush to clean parts of your computer: Cleaning around the keys on the keyboard, exhaust fans and around the bezel of the screen will help promote airflow and reduce heat buildup inside the laptop. Have clean hands: Dirt and oils from your fingers and wrists can eat away from the protective finish on the laptop, keyboard and track pad. Keep food away from your computer: Crumbs can damage the keys preventing them from depressing totally, invite small bugs, damage circuitry and make the laptop look dirty. Keep liquids away from your computer: Liquids can damage or short internal components, corrupt data and make keys stick or not function.
