Looking like you slept in your clothes isn't fashion forward. It's also inappropriate for the office and will certainly not impress your date. If you take just a few minutes to iron your clothes and hang them up, then you'll always be ready to hit the town in style.
How will you know if your clothes need some attention from the iron? Well, if you dug your shirt out of the hamper this morning because you didn't have a chance to do the laundry (up all night playing video games?), it's going to be creased. It will also probably smell. If you want to look nice, take care of your clothes and make sure they're pressed. If you do plan on wearing a garment more than once before laundering it, hang it up.
A better option might be to have your shirts, pants and suits dry-cleaned. You get out of doing your own laundry, and they press your clothes for you before placing them on a hanger wrapped in plastic. All you have to do is pick them up and put them in your closet. While it may cost a bit more money than doing things yourself, the convenience factor makes it well worth what you spend. And, you're guaranteed a professional press job!