However good you think you are at listening, you're most likely wrong. Listening is a full body skill. Agreement and disagreement is not only in literal vocal agreement. How something is phrased can be a clue into what drove the person to say it.
I really don't know how to teach this digitally. I learned just how in-depth listening can be while learning improv at the Upright Citizens Brigade in NYC. The next best thing to doing improv is watching improv so as an exercise when you have some time give this video a watch.
Pay special attention to the start of each new two person scene. One person initiates the scene with an idea, and the other person listens to understand the new world they have just walked into. The look for all kinds of clues about who the other person is, what kind of personality they have, where they are, what they are doing, what their relationship is, and even who they are themselves.
This is a particularly difficult skill to teach digitally where no ears are involved :P
Quick trick to allow yourself to listen easier: When you have something you want to say it's easy to fixate on that and not actually hear what the other person is saying. Cross your fingers behind your back or out of sight to give you a physical reminder of what you wanted to say. This can free up your brain to focus back on what the other person is saying.