I just flew with my DH & DD's, ages 9 & 11, for the first time. Here are some things that I did....
1. Fly direct. Friends of ours that came down a day after we did, had to change planes, and there was a problem at the airport. Flight was delayed, then cancelled, got a new flight, then found a new one that was earlier. Just barely made it to the other plane before it left. Got in at 4:30 am. What would have been a little over 2 hours direct, or less than 5 changing planes, took almost 12 hours.
2. Check all luggage but a "diaper bag" or big purse and any electronics that you take or special items, like blankies or toys. I tried using all carry ons, and 1 checked bag. After checking the one, we all started rolling our carry ons to security. We were in line for security, when we thought the less we needed to carry on luggage. Went back and checked everything but my purse, the camera bag and a soft cooler with some perishable items in it. Do not pack everything in one huge bag. If it is oversized, you get charged extra. When we went back to check the rest, the person in front of us had a huge oversized suitcase. They were charged extra, and it actually cost more than buying a ticket just for their suitcase.
3. Take some snacks & drinks for the flight. Also, chewing gum and or lillipops for the ears during take off and landing.
In my "purse" actually a diaper bag that looks like a messenger bag but is insulated, I had some wipes, antibacterial hand gel, chapstick, sunglasses, some snacks & water bottles, hand lotion, Aleve, tylenol jr, small first aid kit, draminmine, mints and gum. Anything that I might need and if needed would be a pain to get. Then the essentials like wallet, cell phone and plugs, trip and rental information, tickets and my passporter.
4. Take something to keep them entertained on the flight but not too much, they will be wanting to switch again and again.
5. If renting a car make sure you go with a company that has the cars on site. When MCO was expanded, a lot of the rental places are off site. Each rental company that is off site has shuttles to their lots. We used Hertz (off airport), and next time will use Alamo or someone on airport. One less time that I need to load luggage.
6. Take a small totebag that you can use on the flight home, as a carry on for souvenirs.
7. Check out the treads about what to pack. Make a list of everthing that you might want, need or use. Then cross off what doesn't belong, or is duplicates or just won't use, and narrow down the list.
That is all I can think of right now. Have fun!