I tend to pack some odd things that always come in handy but boy does DH pick on me as we pack!
Stain remover (I like Carbona and it's not always easy to find)
Wrinkle releaser spray (I like my clothes to be wrinkle free as soon as I unpack them).
I never bring sneakers - just sandals but I bring a few different pairs. Also bring flip flops to tuck into my bag so if I'm on a wet ride I wear those instead.
Bug spray, sunscreen. I spend extra $ and bring all travel size toiletries so I can just toss them before we leave (frees up more space for purchases).tylenol, etc...
rain panchos...snacks for the kids & stuff to do on the plane...I plan 2 outfits per day per person but also know I'll do a few loads of laundry while I'm there.
everything but the kitchen sink?!?!?!