And the details:
For the firetiger version: Tail is a few strands of fluorescent orange Fishair and Fluorofibre topped with a blend of chartreuse and lime green Fishair. Lower wing is a blend of chartreuse and lime green Fishair with several strands of lime green Krystal Flash. Upper wing is lime green Fishair and peacock Krystal Flash. The wing (but not the tail) is marked with a black Sharpie. Collar is chartreuse marabou with a tuft of red for the throat. Head is chartreuse. Eyes are red/black.
For the white version: Tail is red Krystal Flash topped with white Fishair. Wing is white Fishair topped with silver Krystal Flash. Collar is white marabou. Head is white. Eyes are red/black.
First prepare the head: Shorten stems on backs of eyes to about 1/8" and test-fit into pre-drilled holes on foam head, making sure stems don't protrude into hole for hook shank. Remove eyes and put a small blob of epoxy on each eye hole and insert eyes again. Use enough epoxy so the excess oozes out a little and fills the gaps around the eye. I slide the head onto a toothpick to check for clearance, and then glue the eyes in place with the toothpick inside the head so the epoxy doesn't get inside the hook hole. After the epoxy sets, use a small brush to coat the head with Soft Body and set aside to dry (I leave the head on the toothpick and stick it into my drying wheel).
Now tie the rest of the fly: Crush barb of hook and wrap shank with thread. Tie in tail materials at start of bend. Tail is sparse, perhaps 25-30 strands of material in all. Make a small spreader about 1/4" forward of bend using tag end of Fishair from tail. Lash down about 1/4" of hair, fold tag end back towards tail, lash down again and trim excess, leaving a small bump of Fishair at the fold. Use your thumbnail or bodkin to spread the "bump" around the top half of the shank. It's really more of an edge than a bump -- just enough of a height change to make the wing material flare out when it is lashed tightly against the spreader. Advance thread past spreader and coat spreader with Soft Body or head cement. I also applied a small amount of Soft Body to the first 1/2 inch of the tail to help prevent fouling. After spreader has hardened, lash wing material to top and sides of shank. Wing is sparse (double or triple the amount in tail) and uses the spreader to create full appearance. Wrap thread tightly against edge of spreader to flare the wing material. Lash tag ends of wing material up to hook eye to build up shank diameter to fill hole in foam head. Apply a small amount of Soft Body to wing material where it flares out from spreader to help preserve shape. Allow to set. Test fit the head to see how much room there is for the collar. Rotate the head 90 degrees to get the eye stems past the hook eye. Remove head and tie on collar, making sure to leave room for the head. Tie off thread and apply Soft Body or head cement to the wraps securing the collar. Pull marabou back towards tail, coat hook shank with epoxy and slide head onto shank, rotating head as necessary to get past hook eye and help prevent excess epoxy from dripping. Make sure head is positioned correctly before pushing it against collar, then push head back until hook eye is exposed. Use toothpick or bodkin to work some epoxy into "nose" of head and remove excess epoxy from hook eye. Make final adjustment to head position if necessary and allow epoxy to set.