On my Scandi knife, I use my regular cheap old two sided diamond stone. I use what I assume is the same technique sushi guys use on their knives. Hand on the handle, hand on the spine, knife straight across the stone, then drag it backwards with some consistent pressure sharpening and just light pressure to keep the angle and polish when pushing the other way, in the "cutting" direction, working along the blade. I go until the burr is all along the edge. Flip the knife over, same on the other side, and with both grits. Then I strop it on my belt, 50 times on each side, then back and forth between each side a bunch more times. It gets my SS Frosts Mora razor sharp. Different grinds and profiles I use some different techniques, but the same tools, and strop the same. Something I did notice once, I bought a cheap leather belt at the thrift store to keep as a dedicated strop, and suddenly none of my knives would end up sharp. I tried the belt again, and all was fine again. So, that might be something to look at. My belt is OLD, and I wear it every day. I guess it still works great.