Lay Your Screen Flat
One trick that will make it really easy to clean your MacBook screen is to tilt the computer back 90 degrees so that the screen lays flat and the keyboard is upright where the screen would typically be.
We recommend laying down a soft cloth below the screen to avoid scratching the lid. Since all the weight is on the keyboard side of the MacBook, you’ll need to keep it closer to a 90-degree angle — and you may also want to prop the bottom against something for stability.
However, you’ll find it’s much easier to clean your screen uniformly in this position. You also don’t need to worry about water rolling down the screen and into the hinge area.
Just wipe it gently with a damp, lint-free cloth. If you have a MacBook Pro with a Touch Bar, be careful not to tap that while cleaning, or your MacBook will wake up or boot up. You won’t damage your MacBook by cleaning it while the screen is lit up, but it’s much easier to see smudges and dirt when it’s dark.