A lot of comments here I agree with, but none more than this one.
The best girls are looking for a LIFESTYLE!
This is what's at stake. In the cases of extreme messiness, she will view your untidiness as a lifestyle issue. I know first hand, because I screwed it up before by having woman back at my place when I was not intending to (I've told the story on here before, so I won't go into all the details now).
If you're house is really nice, you may get a bonus point. But primarily, it just can't be a dump, and it has to be clean. You young guys will get a bit of a break. Less is probably expected of you as far as how nice the furniture is, and the girl may just be there for a shag anyway.
Older guys like me aren't afforded this luxury. Even with the younger girls I date, they aren't interested in me because I am better looking that dudes that are their own age, 10 or 15 years younger me. The main reason they aren't dating guys their age is because they are after maturity, stability, etc- and a seriously messy house is a sign of chaos.
The same can be said of any woman that is even remotely looking for something more serious than a just getting laid- they'll see a messy place as a negative reflection of your long term potential. And always remember the general rule that the hotter the girl is, the more options she has, and the more likely she will be to judge you on more seemingly minor aspects of your life that she thinks may affect her future with you adversely.
Don't be lazy about it. It's something you should be doing anyway on your way to becoming a DJ, but you don't want to end up screwing it up once you get that far just because you were unprepared. Make sure your house and car are clean, EVEN when you think you're just going to meet a girl down the street for a quick drink- you never know what may happen, and I have learned this the hard way.
