That's a pretty broad question. If you have specific questions about certain rides or parks you might get something more helpful back.
1. Typically don't use one of your first three on Fantasmic. You can get it as a 4th later on.
2. Don't fall prey to the single rider for RnRC. It doesn't save much time. It's an excellent use of a FP.
3. Sticking with DHS, you don't need one for any of the shows. You can get a decent seat in any of them without.
Anything else more specific, just ask.