"Be polite. It is often expressed as “Do onto others as you would wish them do onto you.” You might not always agree with the writer but learn to communicate your point of view in a more subtle way. The way you wish others would do the same on your blog."

Good points for her on clipmarks too.

I would add, entering a blog, is like being invited to a person's house, before commenting take the time to view the rooms, its decoration have a taste of the entire complex before commenting on a specific piece of furniture.