Good guestion.
I have always been hit and miss when trying to sharpen anything. Sometimes I'll get something I could shave with other times I could used the results for almost anything but cutting.
I know angles have a good deal to do with it but for all my years of trying I'm still haveing trouble with getting the correct one
I've had some luck using a butchers steel (probably wrong way) on a folder. Still have the old boyscout stone, but have long since (ok, I never learned it) forgot what to do with it.