Hey Irish,
I made one form my Mother a while back.
I had her press her palm into some modeling clay, then squeeze it.
It produced a natural shape that was easy for her to hold on to.
Then I reproduced the shape out of "iron wood", then attached it to a shaped dowel of oak.
I measured from her natural hand position (arm down) when she was standing to the floor and added 1/2".
She always has it with her.
I also put some decorative rings near the narrow end (close to the ground) that she could easily grasp.
She and "Pretty Boy" like to take walks and occasionally she'll encounter big dogs that think they can pick on PB.
She'll give them a good whop with the iron wood end... problem solved.
I attached the head of the cane with a 5/8" threaded rod about 4" long and wood glue.
TSA let it through when she flew to see my Uncle, but made a comment about its alternate use. :D