You may scoff, but Dance Dance Revolution is a good way to have fun and actually does impress a goodly number of people.
- Follow the music — You want to hit the arrows when they're in the hollow arrow containers at the top (don't laugh, I lost a couple bucks that way), but the beat is a more reliable metric than just trying to see the right point. Trust me, because I made the mistake of ignoring this advice and it makes things difficult later on.
- Dress appropriately — You may think you look great in platform shoes, oversized pants, or a medieval suit of armor, and maybe you do, but those don't lend themselves to strenuous physical exercise. Make sure you can move freely in whatever you wear, and make sure that if you dress heavily you can remove layers.
Footwear — Make sure you're comfortable in whatever you choose. I usually take off my shoes and play in my socks, because it allows more fluidity. Players who learn at the arcade generally step harder than I do (in decidedly less fluid but cleaner movements) and prefer shoes, though.
- Don't move your feet back to the center — It's tempting but will throw your balance. Plus when you get to more difficult songs it's impossible anyway. Be ready to play from any position you may find your feet in.
- Challenge yourself if you want to get better — I'm not saying you should sqaunder your money by making the first song you pick one you can't do, but that's not an issue at home. If it is, save the hard one for last. If you do songs far harder than you're capable of, you'll come back and find you're capable of much more.
- Enjoy yourself — Remember, it's a game. Having fun is more important than being "good."
The "Looking Cool" Part
Pick and choose from here, you don't need to do them all at once. And several might be mutually exclusive.
- Try using speed modifiers — from Dance Dance Revolution MAX (6th mix) onwards, when you select a song, if you hold the "enter" button you'll be brought to an options menu with this, among other nifty stuff. Bumping it from 1× to 1.5× or 2× (I prefer the latter) will increase the speed of the arrows but not the actual steps (i.e., although the arrows move faster you are moving at the same speed). The benefits are twofold—not only can you more easily read the arrows (trust me, it's easier), allowing you to focus on the physical aspects more, but you can also easily impress people not who don't play themselves. To them, the faster arrows make the game look more difficult.
- Move your arms — Dance Dance Revolution doesn't actually require you to use your arms, but if all the motion is going on below the waist, you'll look at least a little silly. By moving your arms, you'll have something that looks a bit more like "real" dance.
- Spin — If you can incorporate a 360º turn into your steps, people will definitely be impressed.
- Memorize steps — If you can pull the moves with "stealth" mode (hides arrows) on, that's pretty good, and it's even better if you can do this looking away from the screen. Shows confidence in yourself and mastery of the game. At least, unless you fail.
- Freestyle — Sure, getting a perfect score can be fun, and there's nothing wrong with it, but if looking good is your goal, people will be more impressed by handstands and flips and all other matter of tricks and a "D" than a normal dance and an "AAA."
- Always be surrounded by beautiful women — Not sure why, but this seems to work well even while you're not playing.
Above all, though, your personal enjoyment is imperative. I said it already, but it's really, really important. Looking good, playing well, none of it's more important than having a good time. At the end of the day, that's all that counts, so don't take anything in this writeup too seriously.