This question comes from my repeatedly failed attempts to answer questions on other SE websites, where I thought I knew what I was actually talking about.
In one instance, I was trying to explain orbital structures to an OP who appeared like he didn't know much about it in a way I've heard it explained to kids when they learn it for the first time. The other community members didn't like my approach and the apparent lack of scientific terminology in my answer, but I was sincerely trying to answer the question in a way the OP could actually understand. (This answer was deleted, but the question is here: https://chemistry.stackexchange.com/questions/85589/phases-of-atomic-or-molecular-orbitals - any Chemistry.SE mods can actually see it, but I'm not going to undelete it)
Another time, I was answering a question right here on Interpersonal.SE, but perhaps my answer wasn't good enough, or too long, but I got downvoted, and was told not to take the downvotes personally. While I didn't take them personally, I got the feeling that my answer was probably not meeting the OP's requirements, or was just too long. (Here's the question in concern: A friend blocked me, now I want to make amends)
When answering people's questions, how do I know when it's best NOT to answer them, or when it is best left to other people to answer them? As per particular case requirements, how could I have avoided the aforementioned two cases?
I understand that there is a certain degree of subjectivity to my question, and hence I want to add here that being question answerers yourself, there's no better people to ask this to than other members of the SE community. I'm just asking for seasoned advice from the veterans of this trade. :)