Stand tall!
昂首站立

Think of yourself as a puppet with a string coming out of the top of your head. Now imagine that someone's pulling on that string, causing you to sit (or stand) straight and hold your head high, with your chin tucked in slightly. You'll take 10 years off.
把自己想象成是一个牵线木偶，头上有一根线牵着。现在想象有一个人拉着那根线，迫使你坐直了（或站直了），把头高高地扬起。这时候你的下巴会微微收缩，看起来就像年轻了10岁。