I have developed a super simple, and accessible method of metal casting using Fishing Sinkers and Kinetic Sand. Press the item you would like to cast in metal, into a block of Kinetic Sand. Carefully remove it, and a perfect, highly detailed impression will be left in the sand. Place some fishing sinkers* in a crucible (a steal measuring cup will do) and melt them with a propane torch. When molten, carefully pour it into the mold, and let it cool. Remove it from the mold and brush off any sand and that's it. The metal is soft enough that post work can be done with woodworking tools. You can cut off any flashing with a band saw or scroll saw, sand any rough spots, and buff if desired.
*I am using 'Bullet Weights,' they do contain lead, so I hit the finished castings with a few coats of spray lacquer to make them "safer to handle." A safer metal option would be to order something like 'Tin alloy 178-888' or lead free Bismuth. And if you are getting that you might as well order some 'Delft Clay,' and forget the Kinetic Sand, as the results with that will be even better.