hairwings vs. married feather or whole feather or built wings...
the married wings and crest topping take practice, like anything else. a solid foundation is imperative. one of the best books i think you can get is Dr. T.E. Pryce-Tannat's original How to Dress Atlantic Salmon Flies. there have been a couple of reprints since the 1914 original, the latest in 1977. the book is readiliy available from bibliofind.com (amazon.com). the 1977 book is denigrated by an additional section of vastly inferior "modern" flies, tied by who knows whom. One very valuable aspect of the book is that it teaches one how to tie without a vise, which offers some very significant advantages, if you are willing to give it a try.
Michael Radencich's book is also very very nice, some beautifully tied flies, adn good instructional material.
A great way to learn is to attend a workshop. there is an active community of full dress tiers in the pacific northwest. i had the opportunity to learn from derek brown, who is an extremely gifted (world class) full dress tier. he had a ratty old first edition of pryce-tannat's book he carried around with him, all falling apart, which he would reference frequently.
to me, nothing matches the incredible marriage of colors of a full dress fly in the water. the time on the fly takes a while, and i don't recommend dredging with them; although intermediate tips and greased line presentations are ideal. it was a thrill to catch several large salmon in russia on a full dress jock scott, and the steelhead like them too!