No matter how much effort you put into trying to keep people happy, there are always times when a dispute can occur and the cause most of these times comes down to a lack of communication.
So the first step to solving the problem is to try and take emotion out of the equation and make the past the past and have a focus on the future. Always listen to what the opposing case is, then try to understand which parts they are willing to compromise on then simply put forward places your willing to compromise and then can form the basis of a successful issue resolution.
Of course there are plenty of situations that parties are being totally inflexible and this is not going to work but I have always found sitting down with someone and asking them are they willing to comprise on a one or more points if you comprise on somethings as well then things do work out for the best, but after a dispute has occurred its easy to sweep it aside and blame the other party but it would be a great time to make sure how you have communicated to the other parties. Remember you always learn more from your mistakes then your successes so dont miss a chance to make yourself a better person.
Always be careful what life rules you put into place after a bad problem because there is always a tendancy to make global statements that are not effective.