I asked my H to please talk to me respectfully. If he continued, I would tell him I am leaving the room or hanging up and then do so.
I asked him not to bring little S around OW. He tried that about 3 times and each time I confronted him. As pleasantly as I could but firmly.
I asked him to not walk through my office to get to the bathroom(he could walk behind me and see what I was typing on the computer)
These are just a few.
Boundary setting was quite a challenge and it just wasn't a: tell him what I expect and forget it. He didn't like it when I opposed him in anyway. I also had to try not sound like his mother.
I will bring up the thread about setting boundaries for you to read.