My advice, after getting back from a week in October: bring your oldest, rattiest pair of gym shoes! I brought my gym shoes (the ones I wear about 4 times a week on the treadmill), thinking they were very well broken in. Well, they weren't! I got a terrible blister on the bottom of my toe before I realized it. Ended up in flip-flops for the rest of the trip - they were the only shoes that didn't aggravate my blister.
Wish I had brought my oldest, crummiest gym shoes and worn them instead (who cares what your feet look like?). Walking 10 or 12 hours a day is very different than doing a light gym workout, even if you work out most days.