Make sure it is well protected when you are carrying it from place to place. Don't swing your Chromebook along the aisle.
Refrain from eating when you are using the Chromebook to reduce food crumbs in getting in the grooves of the keys.
Never have a open bottle next to your Chromebook. You wouldn't want to risk it.
Does your bag has sufficient padding?
Did you accessorize your Chromebook to distinguish it from your classmate's?
Never rest piles of heavy books on top of the Chromebook.
Stylus should be kept away in the slot if not in use.
Do not use ammonia-based or alcohol wipes on the screen as it is usually protected with a layer of oleophobic surfactant to reduce finger print smudges. Always use a damp cloth with a bit of dishwashing liquid for cleaning. Use a microfibre cloth to reduce too dust specks.
Always use a flat table to rest your Chromebook when you are working on it.
Don't use the Chromebook as your tray plate to carry heavy things. The screen can crack.
Don't use your chromebook when you are taking a bath.
Don't whack the keys, they can come off due to too much force hammering them.