You can’t practice at some things. Putting the cat back in the bag or the toothpaste back in the tube. The undoable, the things that you can’t unsay. The measure twice cut once stuff.
In those cases, a little preparation and reflection go a long way. I think about what's important to say or verify before I say/do the undoable. Afterward, I reflect on how things went, if I learned anything surprising, and how I can improve the process next time. Ideally, I write all this down, so I don't lose any wisdom for the next time I'm faced with a similar challenge.
I'd normally say rinse and repeat here. But the point here is there is no rinse! There is only setting myself up for success when I find myself facing a one-way door.