One of my most used dry flies of all time is definitely the Klinkhåmer designed by Hans van Klinken from the Netherlands. Super nice guy I had the pleasure to tie with at a fair in Italy. It has worked especially well for Grayling up in the north. I usually carry quite a large variation of the pattern with different colors and sizes in my fly box. If a steady riser rejects the fly for the first time you might want to swich to a smaller one or try another color. That usually does the trick and fools the fish to take the fly.
The fly has many names but I remember Hans mentioning that the Klinkhåmer Special was the official one. I’ve seen it go for Klinkhamer, Klinkhammer, Klinkhämmer, Klinkki etc.
Klinkhåmer is supposed to float by its hackle so that the body and hook are under the surface. Wing works well as a sight indicator and is easily seen from afar. Simple tie ones you get the hang of the parachute hackle. Use only the best feathers for the parachute hackle and it will float perfectly every time. If the wind is hard you can cut the wing a bit shorter to minimize its effect.
Hook: Partridge BN #10-20
Rib: Thin mono or tying thread
Body: Dry Fly dubbing
Thorax: Darker dubbing or Peacock herl
Wing: White Polypropylene yarn
Hackle: Color to match the fly