I use a clevis.
I use a clevis.
X2
A clevis is the best option and also probably the safest. Depending on the size of your tractor, a hitch ball can actually shear off at the base if pulled on too hard (especially if you ever have to yank on something.)
When I do that, I use a shackle, at least thats what we call them in the Rigging trade up here, clevis=shackle, same, same.
DevilDog
I use a clevis.
I wouldn't recommend pulling from the "draw bar" ( I assume you're calling the 2 foot long steel bar that goes in the 3 point lift arm ends a draw bar?) at all, if you have the option of using what Kubota calls a "draw bar" mounted solidly under the tractor.
Sean