Careful handling, not grabbing through the screen, not pulling the electric cord, etc.
Physical maintenance and cleaning, from the screen (with the appropriate materials) to the keyboard.
Avoid overcharging. As soon as the battery is at 100%, unplug the electric cord to avoid overcharge.
Keep the laptop properly ventilated. Don't use on top of the bed or pillow cause it might suffocate it. If possible, use fans below it or cooling pads.
Regular software maintenance, like some here have already said. Have your system up to date, use your antivirus and malware protection, know where to surf the web, etc.