The best way to lunge a horse is to teach them how to lunge. I've seen so many people who lunge their horse by standing at the horse's head and then swinging the whip so that the horse gets nervous and starts dancing in circles around the handler, then finally bolts away and hits the end of the lead line and pulling himself into a circle. (I've also done this too).
Lunging takes a series of steps. You want the horse to face away from you so that he can start the lunge. You want the horse to move when you ask. And you want the horse to stop when you ask. This means the horse needs to know how to shoulder-yield, hindquarter yield, and move in the direction you point. All of it needs to be done with cues that don't require you to have to touch the horse, because you want to be able to move the horse's body at a distance.
You would stand on one side of the horse's head facing the horse, and step back. If the horse steps with you, use the shoulder-yield to push the horse back out. Then with the rope in your hand, point in the direction the horse is facing so you take the slack out of the rope and slightly pull the horse in that direction. Cluck or kiss, and if the horse takes even a few steps in the direction, relax and let the horse come to a stop. Do that a few times until you only have to point in the direction you want the horse to go and the horse will go that way. Then begin practicing stopping the horse by giving the hindquarter yield. This will swing the horse's hind end out and bring them to a stop. If you give the hindquarter yield and the horse doesn't swing their hind end out, pull slightly on the lunge line while giving the hindquarter yield and the horse will eventually slow down and turn into you.
This cures so many lunging problems I can't even name them all. It will cure a horse rushing into the lunge, crowding into you as they lunge, leaning on the rope, refusing to stop, and tilting their butt towards you as they lunge just to name a few.