Plan out the design of your engraving. Essentially, you can engrave absolutely any design into a piece of metal so long as it fits within the confines of the area to be engraved. Relief is generally one of the more difficult methods of engraving. This method creates a raised design on a flat background and is achieved by scraping away the background negative space to reveal the raised design.
You can draw your design by either drawing with a pencil directly on the object you are going to engrave or by smoke printing. Smoke printing is coating the surface of a metal object with soot that will serve as the outlining boundaries of your design. You can smoke print by holding the metal surface above a lit candle, far enough away so it does not get hot, but close enough so the surface blackens slightly. After the metal surface has been blackened, carefully place clear tape over the entire object, then peel the tape away from the object. This tape should be just wide enough on all sides to completely cover the side of the object you are engraving. All the soot will now be on the tape and you will clearly see the boundaries of the object, so you can plan the size and layout of the design accordingly. Any residue left by the candle and/or the tape can be easily wiped off with a damp cloth.
Using the engraving tools, etch the general outline of your design. Avoid working in one small area at a time, rather work the entire surface at the same time, going from less detail and adding more detail little by little. Working with the entire design, rather than one area at a time, will maintain the flow and continuity of your design. You can use the tape you printed your design on by reattaching it to the metal surface and simply etching over the tape.
You can find a variety of graving tools on-line and in many art supply stores. You can purchase a basic graver for around $200. Graver tips are usually purchased individually, most costing below $5. Engraving can be an expensive hobby; therefore it is most economical to get the least expensive graver you can find, as well as just a handful of different graver heads, to practice with. As you improve your engraving skills, you may be more comfortable investing more money in more and better tools.
Each engraving tool, called a graver, produces its own unique mark depending on the size and shape of the graving point. To experiment with how each graver acts on metal, you should practice with each one on a piece of scrap metal. Try testing different patterns and pressures to obtain the effects you want.
When you begin etching, you must apply very small amounts of pressure to get the feel for how the metal and engraving tools are going to interact. Working lightly will also reduce the chances that you will make an irreversible mistake on the metal.
Add finer details like shading, and stippling to create the desired effect. Stippling is an easy way to add texture to an engraving. This method is achieved by lightly pressing the graver on the surface of the metal in a series of small dots. You can create different effects such as lights and shadows by varying how close the dots are to each other. The closer the dots are together, the darker the design appears.
After completing your design, buff the piece with a soft cloth to remove any loose shards of metal, and shine with metal polish if desired.