To comment, we should:

• Be respectful towards the receiver.
• Highlighting good points
• Give constructive criticism
• Inquire more by asking questions to engage the blogger
• Describe a little about your connection to the topic (maybe a backstory)
• And of course show interest in the topic
• And last but not least, be friendly

I will try to comment like this and I would love to see others comment to me like this.

I would throw away a comment if it is:

• disrespectful
• criticizing
• harmful
• dismissive
• unfriendly
• unrelated