I recently discovered the Thunderbolt at Smith Canteen, a Brooklyn coffee bar. The Thunderbolt is lemonade with a shot of espresso (don’t judge before you try it). My co-worker Alix Browne was quick to point out its downsides: “Great! First, you strip the enamel from your teeth with the lemon, then stain them with the espresso!” So now I always arm myself with a few packets of these tiny pads, which are moistened with water, sorbitol, hydrogen peroxide, and glycerin. After a hearty sip of jo (or jo and lemonade), just swipe one over your ivories to avoid any potential yellowing. Just be discreet. Wiping teeth is not an attractive sight, even on the best chompers.