The week before Easter seems to be more crowded than after Easter.
I've done Easter twice. My biggest tip, is get to the parks at Opening. You can pretty much get everything done by 11:30-noon. Go back to your hotel and swim, than come back for a few late nites.

At the MK watch the parades in front of Hall of Presidents. You only have to show up 15 minutes early. For Wishes, you can find a decent spot anywhere, since a lot of people leave the park after the parade.

The only park I found bad was Epcot early in the morning. I don't know why, but I guess I just picked a day, when everyone else was there.