obviously it depends on which hand tool. If it’s clippers, you can try cutting up balled tin foil. For others, a good knife sharpener. If you don’t have one, you can try ”sharpening“ against cement, or very fine sand paper.
I have a plastic chair mat under my computer desk that the edges are curled and won't lay flat. Have been unable to bend them back as the plastic is hard
obviously it depends on which hand tool. If it’s clippers, you can try cutting up balled tin foil. For others, a good knife sharpener. If you don’t have one, you can try ”sharpening“ against cement, or very fine sand paper.
I have sharpened some of my pruning blades on the bottom edge of a ceramic cup. Fine sand paper works well too.