In order of importance for me
1. Lower expectations. This is the one thing that I'd say is most important for us (and it ties into number 4 also). We had such high hopes of how every day was going to work out, and what my nephew would do, and none of it happened. It was very frustrating, and towards the end of our trip I said screw it, and had much more fun. My nephew wasn't into riding much, which was annoying because that's why we were there. But in the end he had a GREAT time, and that's truly all that matters. We didn't have every minute planned, but did plan on doing more. Between little things popping up unexpectedly, someone really enjoying something and wanting to do it again, and the day moving fast, my mental plan of how the days were going to work out were nothing like how they happened. This time I have a couple things planned per day (will be FP+ and ADRS and thats it) the rest of day is up in the air.
2. Get park hoppers. While I know some people hate them, we were sorry we didn't get them. Even though it was January and hours were short, we just felt like they would've let us tour better. We went to Epcot on our first day, and while we got tired around 4-5, we figured it was stupid to go back to the resort, so we stuck it out until about 8. If we would've had hoppers, we could've went back another evening (we really didn't see world showcase at all). HS has our favorite rides so we planned two days there (and none at AK), but that was too much. Although I wouldn't have done it different because we really love RNRC, TOT, and TSM.
3. Get the dining plan or at least make more ADR's. Once again, I know some don't like it, but we could make it work. We usually like more expensive things, and we like buffets, so it'd be worth it for us. Even if not, we should've made more ADRs for dinner. We made for Chef Mickey's and Coral Reef and lucked into walking up to Tutto Italia, but we would've liked a nicer meal every other day. Eating QS for lunch then dinner everyday got old. While I know some do have different things, we just got tired of it. We ate too many burgers, and really they weren't that good at the QS locations.
4. Everyone in the party do as you please (if you have multiple kids and not adults that's hard though). It was 4 adults and my 5 year old nephew. We did so much waiting for my brother and nephew. We've decided next time that we don't have to be together at all times. Do what we want, try to be together as much as possible, and everyone will be happy. Nephew wanted to swim, we wanted to tour. If he wants to swim next time, he can more than we let him last time.
5. Stay cheap. If you have the money, then go for it. We are a middle class family, and the extra money wasn't worth it to us. would've rather put that extra money towards better dinners. This is hard for me as I LOVE CR and want to stay in a nice place-not an All Star. While we're still staying on property, we've decided to save some money and go All Stars. We did split stay (which went smooth and I'd do again FYI) at AOA suite and CR TPV. It was amazing, but we really didn't have time to enjoy the resort (did take one day off from parks at AOA). Maybe, like some here, if we went more regularly and didn't tour all day it would be worth it, but we spent very minimal time at CR. It was $500+ per night, and I think that by the time we got to the room to see Wishes, everyone showered, it was about time for bed. Then up in the morning and relax and leave.