How to do I can melt soft metals at home?

so my first idea was to make a furnace out of clay-rich dirt, with a hole for a bellow, using coal as fuel and a steel or aluminium ladle, or one big spoon, to hold the desired metal. I want to melt 'soft metals', with this I mean, low melting points metals, like lead, zinc, copper and tin. I want to make metal objects, just for fun. I know that that some metals are dangerous, like lead, but I had chemistry at school so I am aware of security measures.