Dress a size 12 curved nymph hook with thread. A dry fly hook works, but the Straggle barely absorbs water and the deer hair keeps it up, so the heavier curved hook is fine here and gives a better shape.
Tie in UV Straggle at the rear, run the thread forward to one or two hook-eye lengths behind the eye, and wind the Straggle up the body in close touching turns. Tie it off but do not trim it yet, just tuck it out of the way.
Stack a small pinch of deer hair, about half a pencil in width, pulling out all the underfur first and discarding any tips that will not line up.
Set the wing so the tips just touch the back of the hook, take a couple of loose wraps while holding the hair tight so it cannot spin, work the wraps through to keep it on top, then lock it down. Take a few firm wraps in front to stand the wing up.
Gather the butts and trim them off at an angle, then clean up any strays.
Bring the leftover Straggle back over the top, pushing the wing down, take a wrap there, pull it across to the other side without trapping deer hair, then a couple of wraps in front and trim. That collar is what gives you a hackle effect with no hackle.
Whip finish, pulling the fibres back as you go, and clean up the head. Fish it with floatant.