One of the main things with handforged knives that makes it look good, is even forging. If forge marks are still left in the blade after grinding, it really looks horrible. So a smith either has to grind the entire surface down to depth of each hammer divet, or can just initially forge the surface evenly and carefully. There are several tricks to help reduce the amount of divets you make while forging, but mainly it’s caution and practice.
First, make sure the anvil is at the right height. If it’s too high, the hammer will strike with the bottom edge, or the “chin” of the hammer hitting. If it’s too low, it will be the “forehead” or the top edge of the hammer that hits. To find the correct height, stand erect with hands by your sides, holding the hammer at a 90 degree angle to your body, and mark on the wall or a board exactly where the height of the hammer face is, and stack up the anvil to that height. This makes it so the hammer face is parallel to the face of the anvil, reducing deep marks significantly.
Second, make sure you have a good, firm grip on the hammer. When you grab it, wrap your pinkie finger first then follow the other fingers one by one. Do this until you get used to forging. Before beginning forging, hold the hammer firmly but comfortably, and hold it out directly in front of you. Adjust your grip until the face is facing neither right nor left.
Another tip is using a file or grinder of some sort, very slightly round the hammer so the face is slightly convex, so in case you do hit sideways, it won’t make as deep a mark as a sharp edged hammer would.
The last tip for even forging, is doing light taps at first until you see the workpiece deforming easily, with no evidence of one or the other hammer edge hitting. Once you have that down, give gradually harder and harder strikes, letting off a bit if you start to hit edge first. When starting out forging it feels and acts like writing with your non-dominant hand, you’ll gain muscle memory quickly and forging evenly will take no mental effort at all.