1.) Sound: Listen to music; talk to a friend in person or on the phone
2.) Touch: touch something smooth like a ring or flat stone ("researchers found that people view socializing as tougher after touching a rough object"). Keep this tip in mind for when you'd rather go to sleep than hang out with your friends!
3.) Sight: Colors and light will help keep you alert as well as improve your mood
4.) Smell: Orange, peppermint, or cinnamon scents may help you stay alert when you start to get tired
5.) Taste: Chew gum or eat something with a citrus flavor (or an actual orange or grapefruit)