Background: Recently I writing some answers on what I think there was interesting questions waiting someone to answer them addressing problems they're having trouble with, but not all of my answers received well - some of them getting upvotes (even it not so stellar), but another ones are downvoted. The downvoted ones usually posted before the question closed later with various reasons (including dupes).
I don't want to trigger "meta effect" here (possibly pushing my existing posts into their oblivion), so there are points I want to ask for:
Is there another "hidden rule" for answering other than stated in help center (e.g. "avoid answering possible dupe questions" or "no answering for obvious off-topic questions")?
What should I do to improve existing downvoted answers rather than deleting those things? The duplicates sometimes are not fast enough to detect them, so there is a chance to put well-written answer before getting caught & closed thereafter. Also I think finding possible duplicates is part of OP's responsibility to search before asking.
Should I change my writing style to be more brief when answering? I feel that some people may not received my posts well due to having "too many details" or "not addressing OP's intent properly to the point".
I'm looking for constructive ways so that I can write answers well without fearing too much about downvotes.