Did this for elsewhere but thought you would like to see.

This is a really simple fly but hugely effective.

This is on a size 16 but you can tie it on whatever size you like. Darkest brown silk, waxed, and a starling hackle.

Start your thread and take touching turns over the front 1/3rd of the shank. Tie in a starling hackle by its tip. I like one with a good greenish sheen to it.

Form the body with touching turns of thread. Finish where you tied in the hackle.

Working carefully, as starling hackles are very delicate, twist the hackle and thread together.

Wind hackle and thread together to the head. As you wind tease the hackle fibers back.

Trim out the excess hackle, whip finish and there you have it.