Yup, pretty much it.

Though, cat's tend to learn after one instance though.  So you'll only have
to deal with the guilt once per cat.

I broke my cat of this habit using a little squirt gun.  When I was
sitting in my computer chair and the tried to lay down on the plastic
floor mat behind my chair, I squirted her with the gun.  The second
time she tried it, all I had to do was show her the squirt gun (which
has since been emptied) and she understood not to come near the plastic
chair mat while I was sitting in the chair.