Mount hook, lay a thread base. Stack a bunch of elk hair and measure carefully. You need tail length PLUS enough to pull over the body and form wings. Most Humpy failures are measuring failures.
Tie the hair in with tips extending one shank length past the bend as the tail. Bind the butts along the top of the shank.
Build a smooth thread or floss underbody over the butts to the 60% mark. This color shows through the hair as the "hump."
Pull the hair butts forward over the underbody as a shellback and tie down at the 60% mark.
Lift the remaining tips upright and divide them into two wings with figure-8 wraps.
Wrap two hackles densely behind and in front of the wings. Whip finish.
Substitutions
Overbody/Shellback instead of Elk or deer hair: Elk hair — More buoyant, easier to flare; Deer hair — Finer for smaller sizes
Hackle instead of Grizzly or brown: Mixed grizzly and brown — Adams-style, more buggy; Cree hackle — Multi-colored, replaces mix in one feather