Read about other ideologies straight from the horse's mouth. Socons are my thing, but read socialists, libertarians etc. Helps broaden your mind, and people are better debaters when they have experience with the ideologies' proponents, not Fox/Buzzfeed strawmen.
That is one of the wisest things I have seen on these discussion boards (and so basic). My advice to you would be to start a thread on this topic if you haven't done so already.
Some people get so caught up in advancing their own agenda and stuck in their own bias that they often appear to be close minded (and perhaps they are).
