another method that works great for me is to just tie in a couple herls on either side of hook where tail starts, add a rib and shellback if you want, dub the body, then pull each set of ostrich herls over each side of the abdomen to where your dubbing ended, tie them in, pull your shellback over, and carefully rib it to not trap any of the herl fibers against the abdomen. the result is gulls protruding from only the sides of the abdomen, similar to a lot of nymphs. its pretty easy to do, but the real key is your ribbing. 7x mono seems to work great for me because it accomplishes the task of pinning down the brittle herl fibers to the hook, and it minimizes the amount of hero fibers that get pinned to the abdomen, which helps to accentuate the gill profile.