packing for vacation: part 1

I'm leaving for my 10 day trip to South Carolina on Friday after work, so naturally I started to pack today. I'm driving down with my family, but on the way back I'm flying, so I need to fit everything into a nice carry-on sized suitcase. I'm a textbook overpacker, what if i want to wear that shirt? what if we go hiking? if i wear those shorts i might want to wear this tank top and those ankle boots. what if we go to a ball and i need a fancy dress? what if i suddenly get the urge to go running? so starting today allows me 4 days to think about my outfits and edit it down to (what I think is) a reasonable amount of clothing and shoes.