1) First, you shop. Not just window shopping. But you have to buy something. Preferably something that is an enormous bargain. Like cute earrings for $2.40 because they were 75% off.
2) Then you go home and cook. Cook a great meal. One that involves unhealthy but heart warming foods such as melted cheese or fried chicken wings. Which you proceed to eat despite trying to cut down on fat because you're trying to lose weight.
3) Eat dessert. Make sure you have something both chocolatey and gooey. Or hot and sweet like Milo, hot chocolate, horlicks...Or if it's an especially bad day, you should have all of the above.
4) Hug someone. Preferably someone you know of course. Nothing cures a bad day like a few cuddles.
5) You watch a massive amount of American sitcoms/dramas. Such as Friends, or House or Grey's Anatomy.
And if you're still feeling down, rinse and repeat until desired result is achieved.