Cut two pieces of 2mm foam, one black and one green. They should both be slightly less wide than the hook gap and twice as long as the hook shank in order to give you some material to play with. Any longer than that and it just gets in the way
Take the black piece of foam and tie it in by the triangular cut in a fashion so that the entire triangular section is secured to the hook directly at the base of the hook shank where the bend starts
Next you want to tie down the green foam directly on top of the black foam. Make sure that the two pieces are laying with each other symetrically or the next steps will be more difficult and you might end up having to trim the foam later on.
Now you want to tie in a piece of monofilament along the hook shank on the opposite side from you and extending out the back. The piece should be 3 or four inches long. Here I use 2X tippet. This is also where you will form a dubbing loop and insert your dubbing of choice.