alt Hacker NewsI'm someone who is good at those situations, and what I've learned is that no matter how much you disagree, there's always something that you can agree on. If you're stuck in disagreement, zoom out, and try to move back to a position that you both can agree on.
It's also important to not compromise on values you find personally fundamental for the sake of "finding common ground". It depends on the matters being discussed. Assume good faith, attempt to find common understanding by zooming out, but stand firm when you have zoomed out as far as you feel comfortable. If you push past that, you run the risk of validating insane or dangerous behavior or opinions.