Couple of questions from another site on the tying:
The wee bump of dubbing at the thorax an idea I had to help the hackles stay out a bit to help profile and movement, seems to work well although watch you don't overdo the dubbing, also I like to place a turn of bare thread over the top to secure the dubbing and help keep it compressed. Picking some fibres out also gives a nice wee touch.
Keep rib turns tight so lighter bands are narrow same as on a real quill, certainly not as good as the real thing, but a simpler, easier and more robust way of getting a similar effect. Works very well on buzzers and emerging dries as well.