There are a lot of things that may be common sense to you, but a lot of people think the exact opposite. How do you keep yourself clean? When brushing your teeth, do not rinse afterwards. The fluoride in toothpaste strengthens your teeth, but it needs time to sink in. Spit out everything you can when you're done, but don't rinse, or else you'll remove the fluoride. If you use mouthwash, use it BEFORE you brush to help in freshening your breath and breaking up what's in there already. Assuming you shower every day, you don't necessarily want to wash your hair every day. If you continue to strip the oil out of your hair daily, your body works overtime to make more oil to replace it, which can make your hair more oily than it needs to be. Try washing it every other day, or perhaps once every 3 days. It's a good idea to rinse it every day, though, to make sure that you don't have dirt and skin hanging out in there. USE A NETIPOT. It may look weird, uncomfortable, and disgusting, but it does wonders to clear out allergens and bacteria from your nasal cavity. Guys: Wash your hands BEFORE you use the bathroom. You know exactly where your dick has been, but you can't say the same thing about your hands.