Joe,
The ones I caught (very small sample size) in Montana and Alaska stillwater's were on softhackles like this (with and without a bead head)
Tried for them on some little blue lines in SW Montana with dries I found on some U.K. sites; couldn't find any grayling looking up that trip but brook trout ate them.
Brookes' Fancy
Tommy's Favorite
Like I said, my sample size is very small, but from what I can tell, they're not real picky.
Regards,
Scott
Regards,
Scott