Found this variation of Ian James' fly on a NZ site, the deer hair replacing the dubbing/clipped hackle abdomen of the original. Weight as necessary, although I've read where some folks prefer to add split shot to the leader instead. Change color/size to suit your needs.
hook - Dai Riki 280 #12
thread - Danville 6/0 black
abdomen - deer hair spun/clipped
thorax - dubbing chartreuse
head - ostrich herl black
hackle - black hen
Part 1
mash barb, start thread, wrap to point above barb
you could create a standard spun/clipped body, but using a dubbing loop allows for a sparser body, and the split thread method makes it much easier, for me, to capture the deer hair than a dubbing loop; your choice
clean, stack (butt first) a clump of deer hair
insert in clip, spread evenly; trim tips
split thread, insert clip, slide clip back to allow thread to capture the deer hair and release from the clip
spin the bobbin to create a "chenille"