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Why not invite some friends over and have a birthday party? Hang streamers, balloons, eat cake, play games and watch movies! Just because you are now considered an "adult" by law, does not mean you lose your youth. Enjoy the time with people you love. If you want to have a more "adult" 18th birthday party, there are also plenty of ways to celebrate your new-found freedom. Some people don't require a big blow-out when they turn 18. Spending a few quiet hours at home with your family? Opening presents? Eating cake? If it worked for 17 years, nothing needs to change now. Spend time with the people who love you and relax.   Make it quality time. Organize some spa time with a sibling or parent, or spend time working on cars with your dad. Do something you'd normally do, but take the time to really appreciate it. Most people assume that turning 18 means that these moments will start to dissipate, but that isn't entirely true. You can make them last, even if you start taking on new responsibilities. Make a list of the childhood things you'd like to do, and use your 18th as an opportunity to do all of the things you've always loved doing. Hang out with your brother and watch samurai movies late, or go to your favorite ice cream spot with the family. Remember, turning 18 has more responsibilities, but you don't have to stop being a kid. Try a less common party activity, like camping. You can do this at a park with camping spots, or even in your own backyard. Grab a tent, some snacks, some video games, and a few good friends! It's like an all night hangout but without your parent's over your shoulder. If you want to camp in a park, tent spots are usually about $15 a night, give or take. This can be a great way to bond with your friends while also tasting freedom away from your parents. One good way of celebrating an 18th is throwing a house party for yourself. Depending on the house you've got available, you may want to have a big throw-down or a smaller gathering appropriate for your purposes. Whatever you want to do, make sure you invite an appropriate number of people so you won't have a big crowd spilling onto your lawn and attracting cops.  If you talk about your party on Facebook or other social networking, keep it to private messages. Don't post about your party publicly, or you may have unwanted guests and attention. Consider celebrating multiple 18ths at the same time. If a couple friends are all turning 18, mash up all your parties together to get one big throw-down, rather than a few smaller parties. Think epic. Set up your party with a style that suits your theme, or your own personal taste. You could keep it elegant and tasteful with some nice flower arrangements, photos, and crepe, or you could do it up with a smoke machine, disco ball, and a trap DJ for a grimy dance party. Maybe you want mason jars full of lemonade, a bluegrass band, and hay bales. Decide what kind of vibe you want for your part and go with it.  Quick tip: change your light bulbs from the standard white to red or yellow and set the tone to the house party quickly, cleanly, and cheaply. Prepare your house properly by tucking away all your valuables and things that may get knocked over. Place them in a lockable room, or move things into the garage or a shed. Think about clean-up. If you've got to start scrubbing goo off the floor after the jello-wrestling tank overflowed, you might have a bad start to your 18th year. try to keep it manageable. It's important to have something for your guests to do at your party. This could be anything from games to dancing to movies to cooking. It's your night, so pick something that you will enjoy doing with your closest friends.  Choose something that you and your friends will enjoy doing. If you're a gamer, set up a video game gauntlet and move from room to room in an epic circuit. Super Nintendo in the Attic and Xbox One in the living room. Game your way from floor to floor. If you want to hire a DJ, remember to give them a list of songs to play that you like and your guests will appreciate. As your guests arrive you can always have them write down two or three of their favorite dancing songs and this will ensure they get up and get the party started. If you go with a live band, it's essential that you make sure they'll have enough room, electrical hook-ups, and other materials necessary to play, especially if you're going to pay for it. Make sure they're there early to set up. Nothing ruins a party faster than a call to the cops and a knock on the door. It's common courtesy to warn your neighbors that you're going to have a party and let them know the specific details. Go around the neighborhood to make sure you'll be in the clear. Pro tip: Don't treat it so much like a warning and treat it more like an invitation. Tell the neighbors you're going to have a party for your 18th and that you wanted to let them know they should stop by. Slide a little caveat in there: "Not expecting too many people, but there'll probably be some music. We'll try to have it over with at a reasonable hour. Hope to see you there!"

Summary:
Release the kid in you. Consider a quiet party. Invite a manageable number of people. Think up a theme. Set up the entertainment for the night. Warn the neighbors.