Although I’m very keen on making bits of kit to turn my workshop into a small plastic manufacturing factory. Starting using plastic can be very simple and you can use your wood/ metal working skills quite readily to create things in plastic. Plastic can be quite rewarding as an art material and very simple to get started with. While trawling YouTube I found this https://youtu.be/rpXq6mnbCus and was quite inspired by this young guys simple approach.
He does not recommend shaped moulds but I found they are very simple to make, here I have used a 10mm thick off cut of laminate flooring Or HDF (high density fiber board) which was easy to work with a jigsaw.
I made this walking stick handle just with milk bottles and lids and a conventional oven.
My neighbor makes walking sticks from wood that has had honeysuckle growing up it to produce a spiral stick and we pooled our resources to make this walking stick. The brass part is a plumbing olive.
This method requires allot of finishing but I feel it is worth it.
I made this some time ago but I felt it was remiss of me not to share it with you.