When I use mine I clamp a thick piece of metal to act as a straight edge and rest the flat of the stamp shaft against it to make all the stampings in a straight line and not tilted. A heavy piece underneath if possible to back up the top rail of the frame and act like an anvil is a good idea too. I also using a silver sharpie, wrote "TOP" on the flat part of the stamp shank to avoid making a mistake and stamping something upside down or sideways. As for the hammer, I just use a medium sized ball peen. As suggested, practice on a scrap.