How about for starters: if you have boring notes to offer on someone's web page, send it to them privately, instead of posting it for the approval of the whole community.
Sometimes we have things to say about sites that are relevant to lots of people. But these notes not so much.
I'm probably not great about this either and would be happy if someone took the time to call me out for it.
I've actually done that, several times in this case - 2-3 attempts, about the maximum number I'll generally try. I prefer not to be a complete pest. Be careful in what you presume.
I thought I'd make one more attempt online now when the opportunity presented itself.
And while I try not to flagrantly call out errors on people's stuff, if I see them I'll note them as quietly as possible. On platforms that support it (e.g., G+) that includes a "delete this comment" note, frequently.
I really like Maciej's work. I'd posted a link to "Human Face" just yesterday:
Sometimes we have things to say about sites that are relevant to lots of people. But these notes not so much.
I'm probably not great about this either and would be happy if someone took the time to call me out for it.