I learned this from Jackie at Chico's. (She's a genius.)
I was trying on a jacket and she said I should always push up my sleeves (to the elbow) if possible.
It makes your waist look smaller! Yes, your waist.
You can also get the same effect by rolling up long sleeves to your elbows.
Go to your closet and try it:
Stand in the mirror with the sleeves down, bring your arms straight down next to your waist. Now, push up or roll up your sleeves to your elbows. (The trick is to have the end of the sleeve hit at waist level. Adjust as needed.)
See the difference? It's amazing!
Of course, laying off the chips and cookies works, too.
For more tips, see Kristen.