I go to my local plastics company with a drawing or printout of what I want the finished template to be. They then cut it out of acrylic plastic.
For the twister I would just mark each side with a pen or painters tape at the appropriate places and then I'd be ready.
I have used old Xray film in the past to make my own templates. The only hitch was that I had to destroy all the patient ID info, which was easy to do.
ali