We do the RFC certificates too. We had $75 worth of them for our trip last month. Lunch for 4 at RFC at AK (1 dinner(for me), 1 appetizer(for my wife), 1 kids meal(fed 2 easily[young ones]), and a volcano[Yum!]) was around $40 with our 10% discount, so we left 2 of our $25 certificates, a nice tip for our waitress, and a nice meal for the 4 of us for free. Then we went over to the gift shop where my boys each bought a dinosaur and my wife bought 2 shirts (2 for 7.99) and a jacket at 50% off. Then we had 15% off on top of that. When it was all said and done we had spent $9.00 out of pocket for lunch and a bag full of goodies using our MyPoints certificates.
Another thing we have done is used the points for applebee's certificates (which are even cheaper, 3000 pts for $25) for gifts for people then put the $25 aside that we would have spent on them and bought disney dollars with it.