I ran across this list of "Excellent Rules to Promote Harmony Among Church Members." I am not certain of the author, and the is obviously quite dated (considering the language), but the points are good.
1. To remember that we are all subject to failings of one kind or another.
2. To bear with--and not magnify--each other's infirmities.
3. To pray for one another in our social meetings, and particularly in private.
4. To avoid going from house to house, for the purpose of bearing news and interferring with other people's business.
5. Always turn a deaf ear to any slanderous report and to lay no charge against any person until well founded.
6. If a member be in fault, tell him of it in private, before it is mentioned to others.
7. To watch against the shyness of each other and put the best construction on any action that has the appearance of opposition or resentment.
8. To observe the just rules of Solomon--that is, to leave off contention before it is meddled with.
9. If a member has offended, to consider how Godlike it is to forgive, and how unlike a Christian it is to seek revenge.
10. Remember that it is always a giant artifice of the devil to promote distance and animosities among members of the church; and we should therefore watch against everything that furthers this end.
11. To consider how much more good we can do in the world at large, and in the church in particular, when we are all united in love, than we could do when acting alone, and indulging in a contrary spirit.