We had an existing barb wire fence on the boundary and we have run hinge joint over the top. Then for the internal fencing I use five strand electric on star pickets. The girls are trained to the electric fence now so aren't usually much trouble - except when it shorts and they can tell its not working!
Our biggest problem is the buck paddock. The boys will find a way to weasel out under the hinge joint or if its not supported properly they will go over the top. They are fine most of the time but I have to check all the fencing regularly and keep it in good repair as they will test the fence for weaknesses regularly. They never go far though - either go and see if they can get in the girls paddock or raid the fruit trees and veggies