For occasional use, one or two small 1" x 3" x 1/4" thick EZE-LAP diamond stones like these and two small nails. Place the stone on a convenient log, and tap in a nail at each end to stabilize it. You can put a little water on the stone and sharpen just about any knife. A 400 grit is usually about right, but depending on the steel, you might want a finer or coarser grit. This might be sacrilige, but I also carry a 6 inch bastard file with the point ground off to sharpen my bigger trail knives and axe. I hate carbide scrapers, the edge they make, and the horse they rode in on.