My first MK day is usually intense if it's been a while. Note it is just the wife and I. We currently do not have kids.
Rope drop and enjoy Main Street until the lands open. Work counterclockwise by rope dropping Adventureland and do all the big attractions first...JC, PotC, Splash, BT, HM. Lunch at Columbia Harbor House around 11 and catch the Muppets while in Liberty Square.
Spend the afternoon in Fantasyland. Use FP for Peter Pan and SDMT and endure the lines for Small World, the Carousel, Pooh, Ariel, and Tea Cups if they are under 40 min. waits.
Grab a snack and watch FoF near the Hub. Head to Dumbo and then into TL to use my 3rd FP on SM and do anything with a reasonable wait time. Dinner at place of your choosing around 5:15.
Prior to finding a good spot for HEA, look to see if there are short lines, enough time, or FPs available to do some of the attractions you had to pass by that you want to see. Get some ice cream and enjoy Main Street for a bit before camping out for HEA. Watch the show and then hit up more attractions if hours permit or shop a little. Watch everyone leave from the train station balcony and watch the kiss goodnight.
My 2nd and 3rd days at MK are much more relaxed. The second day is used to try to get to major things I missed on day 1 and then do whatever I feel like. I'll repeat my favorites if they have short waits or FPs available. I will also try to find time to enjoy more passive and thus less crowded attractions...the train, TSI, riverboat, PeopleMover.
The third MK day, if possible, is the least planned. Walk thru the gates and just take it all in the way you were truly meant to. Move slow and just appreciate all the details. If day 3 isn't possible this becomes the day 2 agenda.