Many surrounding areas have been getting fields filled in, so I thought I'd better do Teversham before it started looking like an embarrassingly empty gap in the map. This turned out to be a more complicated exercise than I'd expected!
There are several kinds of field boundary round here: tracks, roads, hedges & fences, drainage ditches, sometimes a change in ground level, or sometimes no boundary at all. Sometimes it's ambiguous and I've had to make judgement calls: often a fence will have become sufficiently overgrown to constitute an effective hedge for some of its length. Ditches, too, often have bushy stuff growing, more or less impenetrably, along at least one side.
Sometimes, too, I can't get close enough to a field boundary to be sure what it consists of, and nor is it clear from the aerial photgraphy. Mostly I've settled on a likely guess, but occasionally I've just had to leave the barrier out (but leave a gap between the fields).
Then there's the question of whether the field areas should share nodes with the barriers which surround them. After a bit of experimentation, I've settled on generally sharing nodes with hedges and fences, but to offset from ditches, roads & tracks. This reflects the reality that farmers generally seem to plough pretty much right up to hedges and fences, but not to ditches, roads or tracks. It also renders reasonably attractively.