It helps to have /follow on an easy to reach keybind.
I use a mouse-thumb button as one bind for follow.

You can also have the runaway interact with another toon, which will have them run back to you.

In PvE, you can usually interact once, and have them stay in range mostly.
In PvP, or with a moving target, you have to mash it and deal with the pathing bugs.

You'll also (rarely) get the camera spins bug, which is cleared by clicking on the active window.
As in Click to Move, anywhere on the screen.. which will correct the camera spin.