15. Smiling!
Want to shave years off of your appearance? Then turn that frown upside down! In one study published in the journal PLOS One, researchers found that smiling faces were more likely to be perceived as younger compared to both neural and sad, frowning faces. And smiling doesn’t just make you look younger: Several studies have shown that the facial expression can even keep the heart healthy and reduce stress levels. And for more reasons to crack a smile, check out these 23 Reasons Smiling is Good for You.