We take a pair of good sneakers (well broken in) and thin moisture wicking socks, we take our Keen sandles and regular flip flops. The first thing I do the minute my key card passes the door, is come out of the shoes, and slip in to the flops!
We've gone with just sneakers, and I've had some of the worst blisters of my life trying that...in fact, if I hadn't had flip flops with me (for using at the pool, knocking around the resort, etc.) I would have been ruined.
My best advice is to take several different types of shoes, wear the heaviest if you're flying and pack the lightest...and trade off, trade off, TRADE OFF!
Another little trick I've found is that if hot spots or pre-cursors to blisters start cover the area with plain ole mole skin (you can buy it at Wal-Mart or any pharmacy) it doesn't slip slide/make the problem worse like band-aids tend to. Once the mole skin is in place, believe me, it STAYS there! It doesn't come pre-cut so make sure you have a small pair of grooming scissors or pocket knife with you.
Have fun!