Glenn O’Brien, writer for GQ manages to muster a few salient points in an otherwise superficial piece, titled The Style Guy’s Guide to Friendship, Schmoozing, and Social Advancement.  I’ll save you the time and provide the takeaways:

On Breaking Up With Friends

Drifting apart is nature’s way. We can still be fond of that old high school chum, but that doesn’t mean we have to keep in touch. (One of the worst effects of the social networks is the past suddenly rearing it’s now-less-attractive head.) I find that it’s best not to explain your course of action as it will only serve to heighten the emotions occasioned by rejection.

On Fighting With Friends

What you say may be forgiven, but it won’t be forgotten, and it hurts a lot more coming from a friend than an enemy.

This can be applied to relationships in general outside of friends. The impermanence of relationships and the importance of treating those how we would like to be treated.  Good advice, if only serving as a reminder.