First of all, someone else paid for the tickets. (: Ours were a Christmas gift, but in all seriousness look for deals. There are always breaks on tickets for any given theme park (pay for a day and get a year, kids are free, etc). We considered crowds, school schedules and weather. We went on a Wednesday (least crowded day) in February (cooler weather & prior to spring breaks). We dressed the kids in bright colors, yellow shirts, so they'd be easy to spot. We made sure we had cash for parking and miscellaneous. We put books and dry erase boards in the backseat for the drive. My camera got fresh batteries and I packed spare clothes and a towel. You never know when there will be an accident, spill or sprinkler to run through. I also put two packs of wet wipes in the car. If you're going anywhere during a hotter time of year put a damp cool cloth in a baggie (you can even freeze it over night). Take turns putting the cloth on the back of everyone's necks. Usually the water fountain water is cool enough to wet them with throughout the day. We put a coat of sunscreen on everyone before we left and brought the bottle for touch ups at lunch.
Speaking of lunch, I packed one in a thermal bag. I brought 8 juice boxes (so we'd have extra for the ride home if we wanted them), a water cup for each kid, 2 cans of Coke, a Tupperware of melon, 4 clementines, fruit snacks, 4 ham sandwiches, a handful of granola bars, graham and regular crackers. I brought one water cup and crackers into the park for snacks, but left everything else in the car. When we got hungry we got our hands stamped and went out to the car. I opened up the back and passed out the food. It was a lovely picnic. Everyone was full (even Isaac!!) and the break from all the stimulation helped us decompress for a bit. Plus we had what we liked rather than being hostage to the one or two overpriced kids meal options.
Aside from preparedness and getting your stuff in order I learned from past experience to adjust my expectations. It's like when you take your kid to a nice restaurant and they insist on ordering a peanut butter and jelly sandwich for $12. You may spend big bucks to take them to a fancy theme park, museum or zoo, but they are going to want to spend most of their time on playground equipment you could have visited for free any day of the week. Don't try to talk them out of it, you'll lose. Just adjust your expectations. Plan on spending a large portion of the day watching their yellow shirts dart around and climb. There are lots of things to do, but they want to hang out in the glorified sand box, no problem. That's the way it is for now, when they get older theme parks will be much more of a blur of fast paced rides. I'm grateful for the small breaks (and happy kids).
Speaking of gratitude, I started the habit of periodically asking the kids what they are grateful for during high excitement events. It keeps things in better perspective for them. On the car ride to the park I asked if they had "thankful hearts" (Veggie Tales language). We discussed how lucky they were to skip school on a Wednesday and take this trip. We talked about how not everyone's Mom and Dad could do that, either. We talked about how big and well behaved they'd been. We told them if they were good here we'd be able to take them other fun places. We also discussed what they were grateful for at the mid point of the day when we had our lunch. I will point out I hadn't had a single fit or demand from a kid at that point (Mike was a different story). We thanked them for their good behavior repeatedly. We also talked about how grateful we were were and what our favorite things were at the end of the day driving home. I was really pleased that no one got upset when it was time to go either. Isaac liked two of the roller coasters best. Riley liked "The flowers shaped like butterflies and the hippo ride". Mike and I agreed the Sesame Street show was the highlight.
We "took turns" a lot because the kids age difference. One kid would wait while the other rode something a lot. I think the merry-go-round and sky ride were the only rides we were able to go on as a family. Isaac wanted to ride roller coasters and he was tall enough for all but one. Most of the rides in the park refused Riley (unfairly in some cases), but there were scattered rides for people under 50" ONLY. This meant Riley had to ride them herself. It made her feel grown up, but it meant we split up a lot. No one complained though. If Riley had to sit out I'd give her some crackers and make up people watching games. She played with the penny machine in picture for about 20min at one point. Aside from the first time we separated and Mike ended up with all the money and I couldn't get Riley's face painted, we did great. Not to worry, we went back and got it painted later.
TWO WEEKS multiply that by four people and factor in the half full hampers before the pain started. It looked a little something this. I started out optimistic, I had a load in each machines and all the hampers rounded up by 8am and help was due within the hour. Everything took a lot longer than I thought so it took me until 8pm to end the process with an impassable living room full of baskets of clean clothes and everyone packed.