A good way to combat bad highlights and spill before trying anything else is usually to raise or lower the light. Using hard light will also increase spill so try to soften it.
So far as I know however, spill is mostly an issue of light intensity on the subject (the object that is being spilled onto) and physical separation from that object.
For example: You have a guy sitting in a chair with a plant next to him and the plant is making his face green so the director says “Gross”
In a perfect world, you could move the plant a little further away. But the directer in this case really wants that plant to be right next to the actor so what you need to do is make sure there’s so much more light hitting your actor than whats reflecting off the plant, that it A.) Barely shows up and B.) (Hopefully) At least gives the colorist what they need to fix it.
I just want to leave a last note to say that this is why set design is so important. These are things to think about when picking camera angles, setting light intensity and deciding where exactly that damn plant should go. 😉