Frank Sawyer was well aware that the heavy fly lines that may be good for proudly casting our weightless dry flies as far as we can, are not very good solution when nymphing. No wonder that today some may like to fly fish with the lightest fly lines like say the old AFTMA standard #1, #2, #3 and even with no fly line at all when nymphing - Sawyer knew it very well why that may be the case. Couple the expertise and the know-how that both Skues and Sawyer accumulated in their time on the water, with the technical advances that modern day rods, lines and tackle offer, no doubt the game may be raised to the next level. This is not to say that anyone will become a great nymphing fly fisherman just by reading those two great fly fishing minds and by getting the latest and greatest fly rod, reel, line etc. - no I dont think so, but some may come close.
Nymphing is a different game, much harder to master than the dry fly. I think some anglers may lack the confidence, the open mind, the feel, the sixth sense for nymphing and maybe they will never be able to acquire the skills to become very good with nymphs, but there is always the dry fly fishing available for them.
A good imagination will help for better nymphing, so one may well be aware and "see" under the water what is going on with his/her nymph or nymphs when fishing. The timing of the strike when no visible clues are signaling the take, the watercraft to find the fish that are more likely to be seduced by nymphs - even when blind fishing and no fish is seen - is all down to the mastery of the craft. And speaking about blind nymphing - both Skues and Sawyer were not fans of the mere "fishing the water" approach and this is where I may differ to them, but it's maybe just a requirement for the peculiarities of the water I fish, because the rivers you fish shape your ways of fly fishing. On the other hand, fishing close and not at distance was what I was only pleased to confirm in my fishing to correspond to what the two Masters advised.
There are many inspirational paragraphs written by that great pair of fly fishing mentors that I especialy like to read and re-read, but here is a piece from Skues I like very much :
"Authorities darken counsel. An authority is a person engaged in the invidious business of stereotyping and disseminating information, frequently incorrect. Angling literature teems with examples. I imagine that few anglers have devoted more time than I have to the study of authorities. From Dame Juliana to the latest issue of the press there is scarcely a book on trout-fly dressing and trout fishing which I have not studied and analyzed, and this conclusion seems to me inevitable. It was not until I realized this that my reading became any use to me. Up to that point I had been swallowing wholesale, with my facts, all sorts of fallacies and inaccuracies, alike in the matter of dressings and their use, and what they were intended to represent. From that point on an author became merely a suggester of experiment —a means of testing and checking my own observations by the water side, and no longer a small god to be believed in and trusted as infallible."