There's an unofficial "maturing" of style as we get older and comfort starts to reign over fashion, but dating at 80 or 18 can mean enjoying the prepping as much as the pairing up. It's very important to feel comfortable on a date and to dress in a way that reflects who you are, but leave the in-house clothes in the house. Worn-out sweat suits and housecoat dresses aren't date attire until you know your date well enough to really get comfy watching a movie on the couch. Wearing the broken-in clothes you love will make you comfortable, but on a date, it's doubtful that they'll make you feel confident and at your best.
Caring about your appearance from head-to-toe is as important for your own self-esteem as it is for the impression you can make on someone of the opposite sex. It can be tempting to try really hard to look young or sexy or sporty or even very formal, but keeping it simple will help you keep the focus on how you feel and who you're with rather than on what you're wearing and how much you need to tug, adjust and suck-it-in to keep it in place. Too much of a good thing on the outside can distract from all of the great stuff on the inside, and too casual or unkempt a look will have the same effect, but with the added assumption that you didn't care enough about the person you're meeting to impress a little, too. Remember getting ready for Friday and Saturday nights in your early decades? Re-create that getting-ready ritual for added anticipation of a date.