I don't have any experience there,
but matching chironies is always a good way to go.
Sometimes a large pink chironie with a glass bead up front
can be good.Take em for krill I think.( like there is krill in the lake )
I would think that you could fish for kokanees the same you fish for trout, so you proably cant go wrong with leeches and such. There was an article in a magazine and the author said that his favourite flies for koks were chironies and mayfly nymphs.
For Kokanee flies the Egg'n'I fly tied in a size 8 3x hook with the egg sac is a hot pink wool works really great for me on Woods lake beside Kalamalka lake. I always out fish the guys that use wedding rings tipped with a maggot or other gear.