I've been having some great luck with this one. Its got some tricks that you can use on other flys as well, specifically the biots and again my split case processes.
Size 14 yellow sally or yellow stone nymph
Danville's 70 Denier orange thread
UTC Ultra Wire BR Red
Start the thread and and wrap the wire down the top of the hook starting at the back of the thorax or 1/3 down the hook from the eye. Make 2 1/2 wraps of the wire back up to creating a "ball".
back your thread down to just in front of the wire ball and tie in the biots with curve facing in using the thread. the wire ball spreads the biots. keep them alligned exactly up both sides by adjusting and then a couple thread wraps to secure.
Spread the biots and hold with a couple thread wraps and dub up with Spectrablend.
though the color is a bit off in the photo, the dub is more yellow than green. make a nice tapper up 2/3 of the hook toward the eye.
Pull the two biots up along the sides and secure with thread.
Starting the first wrap to cover your thread where you tied in the biot tails, wrap the wire up the body, pull back the biot ends and continue wrapping in front of the biots to hold them back. three wraps in front will give you a good lock on the wire and make the fly last longer.
carefully pull the biot ends up to the top, give a couple wraps to hold them and tie in your yellow foam strip (cut from wally world foam sheets, come in a pleathora of colors). keep your thread wraps meaningful. don't want too much thread build up, there is alot more that goes here.
Waspi Antron #2 kit has a great march brown color that I think sets this off and highlights the case and legs on the thorax.
I chose yellow mallard flank for the legs and prepare the feather like so.
one wrap over the feather to hold it, we'll adjust the length later
pull the yellow foam forward, streaching it to conform to a nice roundness and secure with a couple loose-ish wraps...you need it loose enough to now pull the mallard and adjust your leg length. the legs spread out as you shorten them and you can do more about that after the tie is complete. once the legs are just right, secure with three more wraps around the foam and feather.
Trim the foam and mallard feather CLOSE!
Pull one biot up and across to the other side behind the hook eye and hold with one wrap. then pull the other over, one wrap, adjust, another tighter wrap, tighten the biots and secure with two more wraps.
Trim the biots CLOSE! finish off the head starting just behind the eye and working back toward the thorax. apply SHHAN.