I overpacked. I looked at 15 days and no laundry (turns out there WAS laundry, but at the time I did not know that) and thought, whoa.
Now, I am pretty low maintenance. We used to do a quite a bit of camping, and as long as I could wash my face, rinse my hair and don clean underwear, I was good for days and days. But 15 days with the same group of people-not-my-relatives, and a ship cruise with unknown dress requirements for dinner...yikes.
What I packed:
2 pairs of jeans
3 pairs of those nylon travel pants (Eddie Bauer and Columbia) that I hate and will never wear for any other purpose
7 underwears, 3 bras, 6 pairs of socks (all running socks with that nice arch support feature)
2 pairs of walking shoes, 1 pair of running shoes, 1 pair of flats
Raincoat (unlined), raincoat (lined), denim jacket, and a cardigan
2 lightweight fashion scarves
2 tshirt dresses (these came in very handy, paired with leggings and flats)
2 leggings (one capri length)
4 dri-fit tshirts, 5 long sleeve tshirts
TOO. MUCH. STUFF. Although helpful when packing my Carrara marble mortar and pestle.
What I would dump:
Running shoes and clothes. Nice idea, and we did run once along the promenade in Nice, but not worth the space. We did a lot of walking, and climbing, and that should be good enough, right?
Pants: I didn't need 3 pairs of the travel pants. Next time, two pairs at most.
Shirts: 3 each would probably suffice. Handwash in the sink, they dried pretty fast actually, even the non-dri fit ones.
Jackets: One raincoat or the other, not both. Granted, it had snowed 6 inches when we left Michigan, which is why I had the lined coat...
Key for less packing: Woolite for hand washing, and my elastic travel clothesline (no clothes pins needed, got it at REI years ago)