Repeat back what someone said before you disagree with it. Half the fight disappears right there.

A great deal of arguing is not about the issue at all. It is two people trying to be heard. Once somebody knows their point landed accurately, the need to keep pressing it drops away, and what remains is the real disagreement, which is usually smaller. Saying it back also catches the times you had them wrong, and you cannot argue well with a position you never understood.

In your next disagreement, put their point in your own words and ask whether you got it. Wait for the yes before adding anything of your own. Notice how much shorter it gets.