KISS is an acronym for "keep it simple stupid," used as a high-level design goal by computer programmers.
The following two flies have three materials: thread, CA glue and squirrel tail. The glue is a requirement. The hackle fibers won't stay at right angles to the shank without it. #16 hook. 14/0 thread. Fox squirrel. ZapCA. I made the hair fibers surround the shank here, in traditional Catskill fashion. I'll have to experiment with a few tied Sparkle Dun style. Maybe later today.
One clump:
Two clumps: