Here's a nice easy one, yet to catch with it but it looks like it might -
Longshank No 8
4mm bead
Pebbledash + Lumphammer
Coal
Tea strainer
Epoxy
Thick floss
Black thread
Pheasant tail
Smash the pebbledash in this case pea gravel with the lump hammer, add a little coal if you live in a mining area for authenticity, sort the larger lumps out, strain dust out with a tea strainer.
Fit the bead, tie in the floss and wind it in a taper from the bend to the eye with about the same diameter floss as the bead.Tie in a few pheasant tail tips with black thread. Coat all of the the floss with epoxy and either place the aggregates onto the wet surface or roll the prepared fly in a pile of the stone.
A good weighty ballast fly for the grayling - not sure if it works yet, it certainly didn't yesterday but nor did anything else!
This was my first attempt at a natural caddis pattern - it was more like building than tying - next time I'll take more time in placing the stones in a more convincing pattern and (when I buy some) use a dark bead for the head.