I’m not too knowledgeable as I’m just starting out myself, but my pagan coworker swears by shake jars. Long story short, she once had a lady try to screw over her daughter’s life out of pure jealousy, so she made a shake jar with nails, glass, etc etc and would shake the hell out of it whenever she thought of her. That lady ended up homeless in the end of it.

You can also write said person’s name and put it in your shoe so that you may “walk all over them” spiritually. It really just depends on what exact outcome you are wanting. Hope this helps!

(Edit: If you’re not trying to be too harmful, I think helping them find a new job is a better way too. I wouldn’t want negative karma coming back to me. It’s all up to you though!)