Okay, I just watched the Mary Dette video and here are some comments exactly as she described how she tied. Incidently, I was present at both these 2 demonstrations as well as another one she did for the Guild and watched her tie on at least 2 other occasions. Anyway, as far as this video, the first part was done at the CFFC & Museum in 2001:
1. The 'Conover' is tied using hackle 1-1/2 times the hook size. She said, "A size 14(Mustad 94840) gets a size 10 hackle". The tail was as long as the entire hook length. She said she tied most of the Dette dry flies in the last 30 years(since 1970).
2. She tied a Royal Coachman (wet) Interestingly, tails(golden pheasant tippets) were as long as hook. She used 5 turns of herl, 3 turns of floss, 5/6 turns of herl. Then she folded hackle, tied it in by tip and wound it. Wings were concave to each other. At one point in video Poul Jorgensen, Mary and Paul Dahle were on screen.
Next part of video was on 10/16/03 at Guild meeting:
3. Green Drake on a size 12, Mustad 79580. Wing was size 4 and hackle was a size 6 which resulted in both being as long as or slightly longer then the hook length. When wound, hackle was at least 2+ times the gap.
4. Quill Gordon on a size 12. "Use a size 10 hackle" The wings were wood duck with a height of a size 10. She 'eye measured' the tail and made it slightly longer then the hook length. Hackle was easily 2x the gap.
5. March Brown dry: Tied on a size 12 hook with size 10 hackles.

If anyone has this same video they can review and verify my comments above. I know of at least one person who's been on this site since its inception, is highly respected to the extreme, and has this video. Perhaps he will review it and chime in with his observations?

Allan