if you have young kids bring a pad of post it notes - put them over the automatic flush sensor on potties and it saves so much hassle
pack extra batteries or the charger!!
if you sleep with a fan on at night, bring a small one, you will sleep so much better
bring stain stick (like Shout stain remover, but stick form) - you can stain treat a shirt and leave it for up to 3 wks and it will still wash out the stain just fine. Even spaghetti.
Don't forget your CPAP machine or no one but you will sleep as your snoring will keep them all awake. (sleep apnea machine)
keep a noteboook with all the info for hotel stays (if driving and staying overnight other places or going from one place to another) and each night record your thoughts about the day - these will make your memories much more clear
If you have children set up a "lost parent" when you walk into the park so they know what to do if they can't see you - my recommendation is to have them stay absolutely still as they call your first name (not mom or dad) ten times as loud as they can, then if that doesn't work they should find a cast member or a mom with kids to help them.
if you have napping age kids - PLEASE respect their routine!! Missing a nap one day is usually ok, but if you go more then that I will be able to pick you out in a crowd so easily. IMO 90% of the tantrums kids have are caused by being overtired.