Spring Break veteran here. Use Magic Morning/EE if available (or rope drop the opposite park if you don't have it), get to security an hour before your opening time at park, line up at gate 13 or 20 (at
Disneyland, that is-- there are planters that block the lines at those gates and the lines tend to feed into them from adjacent lines, making them a shorter wait. But with any luck you'll be first or nearly first in whatever line). Yes... this means getting to security at or shortly after 6 a.m. with a 7 a.m. MM. Have a plan, use MaxPass to maximize your rides. Get out while the getting's good around 11 a.m. or noon. Keep stacking FPs for the evening. Come back after a long break/lunch/swim/nap at the hotel and see your shows and ride your FPs. With a plan, it's doable even on the worst days, as long as you're resolved to tour early in the day and get out of the parks in the hot, crowded middle of the day.