1. You need more than one pair of sheets and more than one towel. Tap to play or pause GIF Tap to play or pause GIF BuzzFeed Change your damn sheets. At the minimum you should change your sheets twice a month, but if you're a germaphobe, do it weekly. Clean sheets not only feel amazing, but they cut down on allergens and dead skin cells that cling to the fabrics that could potentially keep you from being healthy. Wash your bath towels weekly too, and please, have more than one — especially if you frequently have guests. 2. Know your suit size and shirt size (not small, medium, or large). You should also know and understand the value of a tailored suit. BuzzFeed Whether you have to wear a suit to work or not, it's still very important to invest in at least one (or two — blue and black) if you can. Weddings, graduations, fancy parties, funerals, and other events that pop up in life will require you at some point to wear one. Make sure you look and feel sharp by investing in a quality suit with proper tailoring and you won't have to scramble at the 11th hour. 3. How to sew buttons back onto a shirt or jacket. View this video on YouTube youtube.com At some point a button will fall off of your shirt, jacket, sweater, or whatever other garment. You won't be able to rely on your mom to sew your buttons back on, so make sure you know how to do it. Bonus: If and when you have kids, their buttons will fall off too and you'll know how to fix it for them (or even teach them) in a jiffy! 4. How to make a budget and stick to it. Tap to play or pause GIF Tap to play or pause GIF FOX Making a budget is important (unless you're rich, in which case you can skip this or you already know this, which is why you're rich). But you should be aware of how much money you have coming in and how much is going out. Budgets will also help you plan for rainy days when you need extra cash or to save for a vacation that you really want to go on. They are super-duper important. In today's hyperconnected world, there are a bunch of budget-planning apps that are easy-peasy to use. Start by exploring the App Store on your phone, and peruse the "finance" section to find one that works best for you. 5. How to tie a tie. View this video on YouTube youtube.com OK, so: I'm 29 and I don't know how to tie a tie. I know it's bad, but that doesn't mean I shouldn't know how to do it. I'm fucked if I have to go to a wedding, but you don't have to be like me. If you don't know how to tie a tie, just watch this video and practice and you'll be a pro in no time. 6. How to negotiate: Tap to play or pause GIF Tap to play or pause GIF NBC Negotiating at work is very, very useful. You should feel confident in your skill set and what you bring to the table professionally — and for that reason you should be able to convey your value and receive fair compensation for your worth. Knowing how to skillfully do that is tough, though, so study up. The more you do it, the better you'll get at it. (Negotiating and compromising is also something that will get you a long way if you're in a relationship.) 7. How to pick the right running shoes, because exercise is important. blog.rei.com 8. Which shoes go with which pants. bows-n-ties.com This is a rough guide that you don't have to follow exactly but you can use it as a guide to help plan out your outfits or try new things. 9. How to not pee on yourself when using a urinal. View this image on Imgur Imgur 'Nuff said. 10. And speaking of peeing, you should know how to clean the damn bathroom! Amazon When someone comes over to visit and your bathroom is gross, they're definitely judging you, whether they say something or not. Plus, keeping your bathroom clean is hygienic and cuts down on germs, and you'll probably get sick less. All you need a good sponge and some cleaning solution. If you haven't invested in a toilet brush, do that! And a trashcan in the bathroom is key. 11. How to communicate your feelings. Tap to play or pause GIF Tap to play or pause GIF Red Bull / Via giphy.com Whether you're in a relationship or not, it's important to talk about how you feel and be able to effectively communicate those feelings to others. Start with being honest and then the rest will follow. 12. How to give good and useful advice. Tap to play or pause GIF Tap to play or pause GIF ABC Giving good advice starts with being a good listener. As you get older, your friend group will shrink, and you'll be left with the people you truly care about. At times, they will come to you with problems, and probably vice versa. But based on your experiences, you should know how to offer useful advice to them that can help them get through whatever it is that's troubling them. Obviously you're not obligated to do so, but it's a great skill that will get you a long way in life. 13. Own a sexy pair of underwear. Tap to play or pause GIF Tap to play or pause GIF H&M Owning a sexy pair of underwear can help you to feel more confident — and some of them can even give the illusion of making your junk look bigger. It's a win-win. 14. How to get a haircut you actually like. BuzzFeed Haircuts are important; they can help pull your look together and should be included in any grooming regimen. But figuring out the right haircut for your head shape — and also one that simply looks good on you — can be difficult. If you want to try something new, check out the guide above for a step-by-step breakdown. 15. Know the differences between wines. winefolly.com Chances are you've had wine before, but do you know which wine goes with which foods, or what underlying flavors and notes you're tasting? No? Me neither. Use this guide to figure out what you do and don't like, because as you get older this info will come in handy. 16. Learn how to iron a shirt in 90 seconds. View this video on YouTube youtube.com Iron your damn shirts. It makes them — and you — look so much better. 17. How to tip properly. dailyinfographic.com / Via blog.mint.com Knowing how to tip when you travel is necessary. It's a great way for you to integrate yourself respectfully into a culture that may be different from yours. Use this handy guide to figure out how much to leave across the globe. 18. Stop caring about what other people think. Tap to play or pause GIF Tap to play or pause GIF Paramount You'll reach a point in life where you won't care what other people think about you. That doesn't mean you don't listen to or value others' opinions — but things that mattered so much to you in the past just won't anymore. If you're at a certain age (late twenties through early thirties) and you're still obsessing over what someone else thinks about you, then it's time to hunker down and search within yourself to figure out what matters and what doesn't to you. Fuck the rest. 19. Make sure your pants fit! Paramount Pictures Pant's shouldn't sag. 'Nuff said. 20. Know the different types of screws and what they do. boltdepot.com Knowing the right type of screw can help when you're building furniture, mounting a TV, and doing a bunch of other things around your home. Familiarize yourself with them so you also know exactly which complementary tool to use when installing them. 21. And finally, know how to write a proper thank-you note. Tap to play or pause GIF Tap to play or pause GIF NBC When someone does something nice for you or goes out of their way, make sure to thank them properly by writing a thoughtful note. It might not mean much to you, but it will mean the world to a person by just showing them a small token of your appreciation. This is also the case after a job interview, too. The simplest thank-you note can go a long way. Here are a few examples for some inspiration.