Thanks to Toni for this Frugal Baby Tip!
If you're having problems with gaping at the legs, try double pinning the diaper. It really helps to get a more snug fit.
One thing that helps to make the diaper pins slide easier is stick the pins in soap just before you use them. You can also run them through your hair. The oil from your head is supposed to help. Personally I'm afraid to run them in my head. With my luck, I would jab myself real good!