Slide the bead onto the hook and push it forward out of the way, then lay a thread base from behind the eye back to the start of the bend.
Build a short thread taper where the front of the body will end — you can do it with the body material, but thread makes a more solid ramp.
Catch in one strand each of two colours of Krystal Flash at the front of the body and bind them back to the start of the bend.
Half hitch, park the thread out of the way, clip all four strands in spring-loaded hackle pliers and spin them into an even rope.
Wrap the rope forward to the front of the body, halfway back, then forward again, keeping it thickest at the front so the bead cannot slide back over it; catch it with two turns of thread, snip, and lock it with two whip finishes.
Push the bead back onto the front of the body — far enough forward to leave room for the hackle in front of it, but not so far back that it closes the hook gap. Start the thread in front of the bead and build a thread dam so the bead cannot creep forward.
Tie in a brown partridge feather by the tip in front of the bead, cutting a small V-notch in the tip first, then fold the butt back over itself to lock it and snip the excess.
Take three wraps of the partridge with hackle pliers, sweeping the fibers back, and catch the tip off behind the eye.
Push the fibers back, build a small head, whip finish once and add a drop of head cement.