Get a decent one and check those in use.
A guy I know had one break, so he used baling twine in a loop. He had the knot over the front cinch, it worked back. Ticked the horses belly and the show was pretty good. Rider didn't last.
Last week, a friend's husband was schooling a new horse. Horse was being pretty squirrely, bucking quite a bit. Sunfishing, I'm told. He lasted the ride, but when he unsaddled he noticed a buckle on the keeper had rusted and broken and a metal piece was jabbing the horse in the belly. He felt awful!