Grab a few caffeinated green-tea bags (they don't need to be fancy, even these Everyday Value Green Tea Bags ($4) would do), steep them, and then refrigerate. On those mornings you wake up with dark circles under your eyes or puffiness, hold the cold tea bags under your eyes for a few minutes. The caffeine will go to work tightening skin while the cold depuffs. You can also use black-tea bags to help combat razor burn or other inflamed skin.