Decide what metal will be used for each part. Remember, the thicker the metal, the harder it is to cut with shears, and two layers will be sandwiched together to stabilize the gnome. So, think about how the gnome will be finished.
Option 1 (not made) Cute Gnome Tag Ornament: This is by far the easiest method. Instead of following the outline of the gnome for the bottom stabilizing layer, cut a rectangular piece of 24 gauge sheet slightly longer and wider than the gnome template. A tag shape would look nice. Texture this backplate before adhering all the gnome parts.
Option 2 Make the Gnomes as Shown: Cut a 24 gauge backing slightly larger than the finished Gnome drawing template. If you are sure you will be able to cut around the ornament with shears, a larger piece can be cut. This may give you more design options later.
Both Options: Use 26 gauge sheet for the gnome beard, hat, hat band, hat pom, and nose. The feet can only be added to Option 2. Cut the feet from 22 gauge sheet metal. The hat strip trim and the patches are cut from 28 gauge because they are easier to manipulate when crossing each other. 26 gauge will work, though.
Glue the templates to the chosen sheet metal.