Sheds can drop anywhere, but if you want to maximize your chances of finding that needle in a haystack, concentrate on where the buck will spend the majority of its time, the bedding areas,

yes, fields, paths to the fields (and other feeding areas) are good, but they deer don't (at least around me) spend the majority of the their days in these spots.

If you really want to make sure you are missing anything, you should really grid up an area and walk it out, and the walking should be a nice liesurely slow pace, with lots of stopping and looking back the way you came.