For size 18 and smaller I use a single microfibbett on a side and split it with my thread so it flairs at about a 90 degree angle (to each other, not to the shank -so that would be 45 degrees from the shank). For larger patterns I will use two per side. I mostly fish spring creeks with these patterns. For freestone I will sometimes go with traditional patterns with more traditional dressing.
I also use antron and zelon for shucks but very sparse - a shuck is not bulky but almost transparent - many patterns I have seen use too much - the problem with this stuff is it can float and you want this to ride down just under the film with just the wing and upper portion of the fly showing