"Old age comes on suddenly, and not gradually as is thought." Emily Dickinson
The article at the link describes how
You can select one from a few one-size-fits-all options or stick your appendage in cold, wet plaster to make a cast — which you'll have to wait weeks for.
I've experienced each process, but there's a another option I'm even more familiar with—making a splint from material that can be softened in warm water and then molded to your body. I just got a new splint for my hand and wrist made this way last week. The process seems fairly simple, but it can be time-consuming. I'd like to see this new process demonstrated, and I'll bet I know more than one OT who would like to see it too.