I've recently began to tidy and add official referance numbers of rights of way in the areas I've recently been mapping.
In general I've been ground surveying and then useing bing sat/arial photomaps to get position fixes in the editor [potlatch, id and josm] and some other photomap sources for different angles when the basic vertical image is tough to read on its own due to trees and patchs of week resulution. The ground survey is what I reley on for what to map more than just trace the photo's most of the time.
When I come to working with rights of way I use the definitive mapping and description documents to judge the locations of the way and turning points on the paths as well as providing the details to give [type/referance-number {later I might maybe add official widths too, etc}].
I'm in "discusion" with another contributer but I feel I should mark what is there and in addition with fewer tags (just type that it is designated and the ref and operator) the ways that not supported by ground features but legal paths.
I avoid coping directly by use copying directly. but i read the official souces to guide the ways work out where the waypoints are in bing etc for the official routes.