Get a FP for a ride as soon as you get to the park. Check when you can get your next FP (it's printed on your FP ticket). Get your next FP as soon as you can, and before you use the first FP. This way the time for the next attraction begins to run while you are going on the first ride. Always be holding at least one FP (and more if possible). You sometimes will have to go across the park to get a FP. Only one person in your group has to do this. They can collect everyone's tickets and take them to the FP machines. The rest of the group can wait in line at a ride, get food, shop, go to the rest rooms, etc.
Go on non-FP attractions while waiting for your return window. Or, get in line at a FP attraction. By the time you finish riding it your FP window will, hopefully, have opened and you can ride it twice in a row.
One word of caution. Many people will see the FP return time is 3 hours away, while the wait in the standby line will only be 45 minutes. They will assume it is better to go in the standby line since they will get on the ride sooner. This is not true. The whole idea about FP is that you do not have to wait in as many lines. While waiting for your return time you can go on many other (non-FP) attractions. If you wait the 45 minutes in standby you are not doing anything else but wait in line.