I think the easiest would be to cast aluminium in a plaster mould or sand mould. Did it at school several times, probably the easiest way to do a metal part. Avoid lead and stuff like that : not worth it.
However, you need a little setup for heating, preparing the sand, ... make sure to have the proper protections. Micro droplets or liquid metal can be projected and ARE harmful. Wear glasses, safety boots, heat gloves and arm protections.