We are following a managed grazing approach for our sheep on Breton Meadow Farm. Briefly, this means the sheep are restricted to a relatively small area (using electric netting) where they are allowed to graze for a short. The purpose of this is to encourage the sheep to eat more of the forage available instead of picking and choosing what they like. In theory, they learn that the forage is limited and greedily eat everything they can find. In practice, they are still choosy unless you severely restrict the available forage and move them very frequently (e.g. daily or twice daily).
We have fallen into a pattern of moving the sheep two or three times a week. This seems compatible with our schedules and avoids the sheep coming back to eat the new shoots that sprout from plants that have been eaten. With this approach, there are areas that are being more heavily grazed than we desire as well as areas that are being less heavily grazed than we desire.
As an experiment, I have taken to documenting the areas the sheep are grazing. To set the context a bit, our farm has about 3.3 acres and is surrounded by a permanent fence that skirts around the house, garage and back yard. There is also a gully in back that the fence also avoids. The land is oriented with the front facing due south. The back forty or fifty feet has many trees and there are trees along the street in front. There are about a dozen significant trees scattered elsewhere on the property. There is a black raspberry patch in the middle of the southwest part of the pasture that we are trying to protect from the sheep.