I am not from Miami, and the last time I saw someone use a hoof rasp I still lived on the dessert side of Washington State (about 45 mi. from where they hold the Pendleton Roundup). It was important to both my grandfathers that I learn the basics of riding and caring for horses, but that was a very long time ago.

I think a lot of us use the 3 ft rule. In my case, "not too visible to a man on horseback" might be a good rule.