think about if your riding a bike, or a car, or a motorcycle. you want to be as much long as a distance away as the object that your on. so, you should be about one horse apart from each other.
Use a slip knot or i prefer a tie ring. Also, give the horse a foot or two of slack and keep a close eye on him or her. NEVER leave a tied horse unattended.
I'm a horse rider. i rope and I've been with horses all my life. you should tie your horses with a halter. tie the halter loose. never tie the halter tight. just in case your horse spooks!! you don't...