Hi Foggy. My free hand technique is to lay the edge of the blade flat on my thumb nail. I start sliding it back and forth at the same time I raise the back up until the edge starts to cut into the nail. This is the angle which I sharpen. I start with 3-5 strokes each side. Later down to one stroke each side. I finish by stropping on my pant leg or cardboard, something of that medium. Finish it off by slicing some paper or shaving hair. This is the method I learned when I was an Army Ranger back in the 80's.