With this type of halter it is important to note that some horses (example: Cole my incredibly smart lesson horse) figure out that all he has to do is jerk his head a certain way when he's tied and I'm not looking, and the leather piece pops and breaks, then Cole is free to wander away and eat grass. For him it's a very calculated maneuver, not done out of fear but out of a reasoned thought process which results in grazing. So for horses like him I will often use a rope halter, shown in the next photo.
It's worth noting that when I teach a horse to tie, I like to use something that doesn't necessarily break, but will slide through the blocker tie. I often do this in the round pen with a long lead rope to start, so that the horse can back up and pull on the rope, but he will run out of space and his buns will touch the other side of the round pen before he runs out of rope. In this way he learns he's not tied solid (thus preventing fear), but he doesn't learn that he can get loose, either. I also don't leave him unattended, so that I can immediately gather the rope and return him to the proper distance from the hitch rail should he pull back.