A couple weeks ago I had the chance to go ride with professional reining trainer, Jonathan Gauthier who owns the channel @horsetrainingpro. He offered some great tips to improve a horse's stops, as well as changing the perspective about how we ask for it!
Here's his video on evaluating a ranch riding prospect:
https://youtu.be/YdSpSFVAkKc
And one of my other favorites of his "10 Things Good Trainers Do":
https://youtu.be/_nrnuSlBB6s
Check out his channel and be sure to subscribe!