A good tip is to rush for the big-ticket attraction at park opening, ride it, then get a FP for it. While you wait for that FP to come due, ride another big ticket, then come back when your FP is ready. That way, you'll have done three rides on two of the park's big attractions, and all within the first hour (or less even!).
A popular strategty at the MK is to do this with Splash and Big Thunder mountains, or with Space Mountain and Buzz Lightyear. At Epcot, this works for Soarin' and Test Track (though it's a bit of walking!). At MGM, it's best on Tower of Terror and Rock 'n' Rollercoaster. At Ak, you'd do this for EE and Kilimanjaro Safaris (or Kali River Rapids).
Later in the day, you still use fastpasses, but not in the same fashion. Because return times are getting longer, you might FP Big Thunder, and then do some of the low-key attractions in the area (Tom Sawyer Island, Bear Jamboree, etc), because the line for Splash Mtn is 60 minutes! In the mornings, FPs let you jam in an extra ride or two while you're dashing around to beat the crush. In the afternoons, FPs let you take in the smaller attractions while your FP 'waits' in line a couple hours for you.