The biggest thing about any swing is that it has to be directed to your target. The biggest mistake heelers make is putting too much angle on their swing. They’ll have it way over on the left side, with their tip turning over past the left hock without leverage to bring the tip through. They’ll have to make a big change to make their delivery work—and rarely does it.
One reason this happens is that your elbow is too high. Don’t drop your elbow, but you don’t want it too high either. I’d say 90 degrees from your shoulder is a hair too low. You want to keep your elbow a bit above that 90-degree mark, but definitely not straight up in the air.
Another reason you might not have your tip to your target is because you’re turning your wrist over too late. The goal is to turn your hand over sooner at the right leg. I want to turn my hand over to the outside of the right leg, because otherwise you’ll handcuff yourself.
I want some angle on my rope, but it still has to be directed to my target and my right shoulder has to be behind my left shoulder. I want to lead with my left shoulder, with my tip directed to where it can come out of my swing at any time to deliver.