It contains the advice or opinions of one or more Wikipedia contributors. This page is not an encyclopedia article, nor is it one of Wikipedia's policies or guidelines, as it has not been thoroughly vetted by the community. Some essays represent widespread norms; others only represent minority viewpoints.
This page in a nutshell: Focus on the positives of a user more than the negatives. Try earning them carrots rather than sticks.
Thank, rather than criticize. Try to thank other users more than you criticize them. No one wants to attempt to contribute to the encyclopedia anyone can edit and, in return, receive a slap in the face. Mistakes should be reacted to with counsel, not criticism.
If Wikipedia wants verifiability, it must invest in civility. Most people will only edit Wikipedia if Wikipedia is a pleasant place to be. Thus, a large variety of subjects will only be covered, and covered with neutrality, and the numerous and varied editors capable of providing this coverage will only participate, if users are rewarded more than punished by others.
Parts and aspects of articles may and should be criticized, but editors should not be, and care should be taken to not criticize an article in a way that does criticize editors. Furthermore, if one contacts a specific editor regarding the flaws of an article, one should attempt to thank them for their contribution while suggesting improvements to the article rather than bemoan the fact that they exist and made the article worse.
Keep in mind that if one dislikes one aspect of an article created by another editor, that editor is not an obstacle to creating a quality article, even if the editor wishes to keep the aspect one dislikes. Rather, they carried out the work to create a nearly perfect article. Not you.