To some degree, this is the stuff of social anxiety --"ZOMG I am LISTENING WRONG I didn't even know you could screw that up. D:" But it's particularly interesting to be conscious of the different response styles when you're the speaker: "when I am saying something, why am I saying it? What sort of response do I want?"
Frequently, I write about things where I don't have a strong need to receive or avoid a particular kind of engagement. If I write about what I did on my staycation or post a book review or my exercise routine, my purpose is to chronicle my life for my future reference and to share bits of me for the entertainment of my friends. Any response to these that's well-intended will be fine. I am not going to be upset if someone disagrees with my review or offers cleaning advice or suggests an alteration to my biking habits. I may not agree or accept the suggestions, and I wasn't looking for them, but I am perfectly happy to have them offered.
But sometimes I write something specifically to get advice: "why can't I get this database to do X?" and in those cases I'll stipulate I want advice: "Suggestions welcome!"
But when advice isn't welcome, like if I'm whinging about going to my day job or because I got poison ivy, and all I want is sympathy and not suggestions on how to save more money or poison-ivy-avoidance strategies (step 1: stay inside and avoid all greenery), I don't usually put up a disclaimer "not looking for advice".
... actually, a lot of the things I don't want to hear advice about, I just don't *write* about. Many of the things that I'd like my ideas to be heard about, I don't write, either. Religion. Politics. Finance, even, to a lesser degree. Topics so fraught that it's very easy to trigger defensive reactions in the listener, or to have a response trigger the same in me. Sometimes it's not even that I mind listening to contrary responses, but that I often don't have anything to add in reply. I don't start the conversation because I don't know how to end it. "Agree to disagree" doesn't seem to work as well as I might hope.
Anyway, I am wondering now if it's feasible for the person who introduces a topic also to define what they hope to gain from talking about it. Explicitly, instead of implicitly, via the dozens of social rules and cues we imperfectly share across our culture. This seems, perhaps, more achievable in blogging -- "my journal, my guidelines" -- than in normal conversation. It does seem a bit awkward, but maybe less so than 'I'm never going to talk about this at all.'