What are all the things you can use as a mould? With some creativity, I would imagine the list would be longer than the human genome. What material are you trying to mould and what are you trying to make of it? Please narrow it down so we can really help. If you're casting silver, gold, bronze or lead... A lost-wax method is common and the process creates a plaster mould. If you're moulding chocolate, vacuum-formed plastic is common. Another process I can think of is using wet sand compressed into a mould. This works well for some moulded ceramics and some metal working. Again, please explain.