Here's some photographic step by step instructions for tying the Bi-Visible Dry Flies. They are great when pulled through waves on a windy day. Use any size of dry fly hook you want and also the density of the body hackle is up to you.
Materials :-
Hook - Dry Fly
Thread - Black
Tail - Black Cock Hackle Fibres
Body Hackle - Black Genetic Cock Hackle
Head Hackle - Grizzle , White or Cream (Slightly longer barb length than body hackle)
Bi-Visible ~ Black / White
The pattern here is the black and white version which I find most effective, others patterns include the olive/white and red game / white.