Straighten out the seat belt straps before you fasten yourself into your seat. A twisted seat belt strap puts you at risk for receiving cuts if you should experience rough turbulence or have to make an emergency landing.
Adjust the length of the seat belt to make sure it fits snugly. Take the female buckle and pull it away from your body. To make the belt more snug pull the section of the belt strap that is hanging loose. Take the male buckle and slid it inside the female buckle until it clicks. Pull the loose strap to make sure the belt is snug.
Use your seat belt for the entire duration of the flight. You should only unbuckle your seat belt when going to the restroom. Airline safety standards require the seat belt to be fastened whenever the seat belt light is on but you should keep it fastened whenever you are seated -- even if the light is off. Pilots will activate the light when there is known risk but turbulence is difficult to detect and may strike at any time without warning.