If your hotel has a free cancellation policy, and if it’s all in budget, consider one of the onsite hotels that give you Express Passes. Otherwise, aim to be hitting security at least 30-45 minutes before park opening to allow time for security, walking through CityWalk and ticketing. Have your tickets in hand too.
Hit all your must rides in the AM, shows and less popular rides midday, back to rides around 4-5pm. Eat at off times. Lunch 11-11:30 arrival, early dinner or just lots of snacks and a late dinner at CityWalk (or near your hotel).
Get the wait time app. Be sure and put your phone in airplane mode or adjust location services as the apps are battery killers otherwise. Bring a back up portable charger.
Pack light! We made do with my small cross body bag. Lockers are free at the rides that require them- many do. PSA for the day- there is no reason for the whole family to go to the lockers. Some of the areas are very small and unnecessary people are just clutter.
3 days is always better. Plenty of time to relax and see everything. Buy at least one interactive wand. You can have the empty box sent to near the park exit for pick up on your way out that night. Better than carrying around an empty box all day.
Have fun!