Also see: how to wear the same thing every day and have it be socially acceptable.
Basically, when I'm home all day by myself studying, the last thing I really want to think about is getting dressed, so I almost always grab a white v-neck and a pair of shorts. But every once in a while I venture out to Walmart, or Chili's, or some other fine establishment in town where I want to look a little more put together. Enter: accessories. And no one knows the difference.
20/22 Old Navy shorts; Thrifted scarf; Target flats.
21/22 Old Navy shorts (that I still need to hem); Aeropostale scarf; Target flats.
22/22 Old Navy shorts; Thrifted belt and shoes; Necklace borrowed from Mom.