one day at a time... every park has a lot to offer. A day per park will let ya see the highlights, a good guide book would help narrow what things are must see.
MK... Pirates, Jungle Cruise, Big Thunder, Splash Mtn, Haunted Mansion, Hall of Presidents, Small World, Space Mountain, Laugh Floor Comedy Club.
Epcot... Soarin, Honey I Shrunk the Audience, Test Track, Mission: Space, American Adventure.
Studios... Rockin Roller Coaster, Tower of Terror, Great Movie Ride, Beauty and the Beast, Star Tours.
AK... Festival of the Lion King, Safari, Flights of Wonder, Expedition Everest, Finding Nemo, It's tough to be a bug.
At GF photo shoot ya get 20 min. with the photographer, not really enough time to change out fits, all the shoots are outdoors.
Don't overplan, if something goes a little wrong because of weather, or transportation issues, people have a tendency to freak out... a list of must do, and would like to do solves that kinda issue. If you have a large party, or small children... remember this will be overwhelming, don't be the mom that is screaming at the kids, "stop crying and have more fun", while dragging them by the arm though the crowd.
Ya didn't mention time of year, or who is going with ya... so advice is kinda general. Get to the parks early, at opening... you can get more done in the first couple hours when everyone else is sleeping in then you can the rest of the day. Drink lots of water, the counter service restaurants will give ya a big glass of ice water if you ask. Don't schedule meals (dinner) to early or to late such that you miss a night time spectacular.
while at the parks watch for the folks that are "Cult of the Lime Green Mickey Head"...
home depot has mickey paint swatches, the color of lime green was decided in an ancient and secret ceremony going back to the far reaches of time. Disboard veterans laminate them and hang them off of backpacks, camera straps, hats, make t - shirts out of them, etc. This is so we can identify each other, but feel free to semi calmly ask them for help.