First I usually try to figure out what is causing the conflict. There is usually a reason. Most people don't want to argue or disagree so there is usually something else that is going on. I am on a soccer team and there is someone on the team that recently has been very difficult to deal with. He wasn't always like this. It wasn't just me that was getting this treatment it was the entire team. One day after practice, I asked him out for a beer and got him into a setting that was neutral for both of us and just asked him "what's going on with you? You aren't your normal self, is everything OK?" It turned out that his company was going through some tough times and he was worried about having to let some folks go. We talked for a while, and things got better at practices. I always made it a point to greet him personally when I saw him and let him know he had an ally and was watching out for him. I usually try to find out what is behind the conflict.