Here's a healthy habit to get into: Wash your reusable water bottles. Over time, reusable bottles can harbor unhealthy bacteria that can make you sick. Every few days, use your dishwasher to sanitize both the bottle and cap. If your bottle isn't dishwasher-safe, you can also fill about one-fifth of the bottle with white vinegar and the rest with water. Let it sit overnight and rinse it out in the morning so it's clean and almost as good as new. When it's time to replace it, be sure to recycle it if you can.