[Catfishman]

I like these:

Watch their hands if you suspect something is up.

Aim, if you have enough time.

Put your front sight on him if you have less time.

Point shoot from your bellybutton if you have no time.

If someone completely gets the drop on you, you might want to just run and seek cover, maybe shove and run.

I agree that distance is usually your friend.

I think having a "rotation" of guns is a mistake. It hurts familiarity. Remember, you have self defense guns and you have your collection.