My right ankle is prone to turning sometimes, and seems to have been a bit on the weak side after an accident years ago.

I now wear trainers instead of boots when I go hiking and it seems to make no difference to whether my ankle turns or not. But it still happens occasionally and I wonder if wearing a sports ankle brace would be any use?

You can get stiffened ankle braces that will pretty much prevent your ankle turning. From my experience you might find other problems due to rubbing etc.

Don't think long term use of them is a good idea unless nothing can be done to improve the state of your ankle.

Try some exercises to strengthen the ankle and make/buy a wobble board, really beneficial for that.

Get a wobble board

Wobble Board
I'm thinking about getting the adjustable one with the blue rocker, or one of these.
Balance cushion

The wobble board looks interesting. Thanks for drawing my attention to that both of you.