Keep in mind that if you have children in your party, their wishes can be used by the adults. For instance, since it costs about $54 a night for the kids, each of their wishes costs $26. When you go out to eat it's not likely that your child can eat $26 worth of food, but as an adult you definitely can (I'm assuming anyway!). You always have the option of using one of "their" wishes since they get lumped together anyway, for yourself.
I've found the best use of wishes to be tours, dinner shows, spa treatments and Cirque du Soleil. You'll always come out ahead if you use wishes for these sorts of things. You can also come out ahead at some restaurants, assuming you'll be eating at least $34/$26 (cost of adult/child wish) worth of food.
Good luck!!