Since my kids got old enough that I haven't needed to bring things like spare underwear for a potty-training child or autograph books, I've usually used a very small crossbody purse (just a couple of inches bigger than my phone) with tons of pockets.
It holds:
- my phone, with a ziploc bag if I'll be going on any water rides
- sunglasses
- a couple of credit/insurance cards, and if needed for tips, cash
- a couple of Band-Aids and Tylenol capsules
- a 3x5 card with touring plans
- if the weather demands, a disposable rain poncho or a tube of sunblock
(We don't bring water bottles -- we just get iced water from CS when we're thirsty -- and if we think we'll need a sweatshirt later, we wear it tied around our waist). A crossbody bag is effortless and you never have to remove it-- not to eat, not to use the restroom, and not on any attractions, since it can be shifted and tucked out of the way of any restraint system. It's perfect for those who, like me, might otherwise set down and forget their bag on occasion.
For our upcoming trip, I'll be trying a couple of new things: (1) bagless, at least at HS, with my phone in a cargo short zipper pocket; and (2) using a Dickies waist pack, now that I'm in my 40s and not trying to win any fashion competitions. The one downside of a crossbody is that if you are ample-chested, the crossbody strap tends to thread its way between your [*I keep getting censored when I use the correct word -- so shall we say, bazooms?] and press your shirt between them as if to shout to the world, "check these babies OUT!!" A waist pack has all the same benefits as as a crossbody, without that particular drawback.