I use four protective boots on my horse every ride and whenever I lunge him, specifically the Euro-Pro Heidi boots for the front and the Euro-Pro Askan boots for the hind. When we get serious about jumping I will buy some jumping boots like my first horse had, which were Equifit T-boot EXP model, 2 front and 2 hind.
I keep Magic and Tanner in front sports boots when they run barrels, and I'd like to keep some boots on Bandit when I'm driving him, but haven't found any his size yet. Magic actually won't run as well without boots. ^^; On the trail... no boots.