Align two hackle feathers on top of each other. Tie them in with the dull side facing up. Start tying just in front of the wing with a few loose turn, then increase thread tension. Make one or two rounds over the stems at the back of the wing.
Dub the first part of the thorax – leave 3-4 millimeters free in front to make room for the foam in later steps.
Use fingers or a hackle plier to create an ordinary parachute hackle. Two turns are ok, three is plenty. Secure the hackle. Do not worry about stray barbules, you can hair dress them later. Cut the hackle.
Cut some of the hackle barbules in front – creating a V-shape. Moisten your fingers and pull them back. This is the first step in forming the delta wing.
Moisten your fingertips, and evenly drag the hackle to each side of the wing. You do want to form a delta-wing on this fly. No barbules in front. Then take one of the two foam shoulders that’s now pointing upwards at the back of the wing, and fold it and stretch it forwards across the hook shank in front of the wing. Then take the other and stretch it forwards, but to the opposite side. Make sure as few barbules are caught as possible. Tie in the foam about 2 millimeters from the eye of the hook. Cut of the remaining parts.
Secure the foam by forming a tapered head. Prepare a dubbing noodle
Dub the final part of the thorax.
Tie off, and use head cement to secure. Trim any stray barbules that’s now probably stuck under the thorax.