Get to the park at opening or earlier, but avoid the EMH park. Get the popular rides out of the way first.
If you are going to a water park, get there at opening (especially if you want to do Summit Plummet, b/c at 9:15, the wait is at least 1/2 hour and that's as short as it gets for the day unless they clear the line b/c of thunderstorms). Or go after 3 when most of the people are leaving.
Stay at a resort near a park, one that doesn't have need bus service. Much more convenient for mid-day breaks. If you have a car, go ahead and drive to the park. (Disney transport is OK if you plan to stay all day, but for park hopping or resort-to-resort, a car is the best.) The shuttles are pretty good or if you are a member of
AAA, get their diamond pass so you can park up front.
At the MK, take advantage of riding during the Spectro Magic parade. You can virtually walk onto Splash and Big Thunder. If you plan to watch wishes, do it on an E-ride night. The bus lines are horrible at MK close. (We waited over an hour to get a bus back to Pop.) Better to use that time to ride when it's cool, plus you're not getting back much later than the masses.
We also left our Misty mate back at the room. We did fill our Brita bottles up with ice from the resort before leaving out. That was a real $ saver. If you go to the AK, get a child's meal voucher. The child's meal is enough for an adult. Plus you get an ice cram bar or pop corn voucher, plus a soft drink or water voucher.