Dandruff flies

Okay, big hole in my fly box. Realized that all my flies are designed
for Eastern streams. BFF.... Big Friggen Flies. When you tie a
wiggle nymph with two size 8s, you got big flies. However, Western
streams require something a bit finer. Size 18-26 with an occasional
#32 are the primary flies used (though a size 14 pheasant tail will
take a serious fish, just don't tell the locals 'cause they'll tell
you it won't work).
Working with Ed Engle's book "Tying Small Flies." I also have
"Fishing Small Flies." Need to fill up a box with the micro flies
before the end of the Winter.
So, the question is, what is your favorite dandruff fly and where do
you use it?
Frank Reid