Over the last few years, dubbing nymphs (abdomen/thorax) has given way to more segmented, leaner abdomens with the thorax having some dubbing behind the ubiquitous bead head. That said, a bristly, impressionistic nymph/emerger pattern still holds my imagination. True, segmentation does suggest a realistic, recognizable image for the fish. But, that movement of fibers and hairs encased in bubbles speaks to a succulent morsel as well.
Whether one twists dubbing onto a single strand of tying thread, splits the thread and inserts dubbing, creates a dubbing loop (with the above tools) or builds your own dubbing brushes, the dubbed nymph body is suggestive of life.
It is easy to build, in some instances, too thick of a body. It is necessary to study the four types of mayfly nymphs (swimmer, crawler, clinger, burrower) and see how they relate to the nymphs you will try to copy. Match the thickness of the abdomen and thorax as appropriate to the type of mayfly nymphs.
Study the Caddis pupa’s, the Stonefly Nymphs, the Dragon Fly Nymphs, Scuds and Sculpins. How could dubbing provide the suggestion of life beneath the surface, in the surface or on the surface (Ultra Fine dubbing for dry flies too).
I have highlighted this UK Fly Dressing Dubbing piece before. I reviewed it again and it is a lot of effort put forth and is still relevent. There are a few other sites that discuss dubbing, but none that I have found so far as comprehensively as ScotFly’s Effort (here too).