I believe what my parents did was tie a sheet over the top of the crib when my sister started doing that. They were concerned about her falling out once she'd reached the top.
But that was in the unenlightened 60's.
It worked, though!![]()
My parents pined the feet of my pajama's together to keep me from climbing out of my crib, but I was under a year old-walked early. They said I would hook my foot on the railing of the crib and just slide off on the other side

When we moved DS17 out of his crib we bought him a double bed. He fell out of bed once and figured out how to stay in bed after that. We gated his door for a while and he figured out that he had to stay in his room. He never really got into our bed unless he had a bad dream. DD14 on the other had crawled in every night. She would wake us up and ask if it was ok, finally we just told her to stop waking us up and crawl up into bed from the bottom so we didn't wake up. This was after we decided to close our door one night to see if she would stay out and found her sleeping in the hallway in the morning.