I usually prefer answering questions that are interesting to answer. I will mostly not pick questions for which I may not have answer for even 100 words. I also skip topics that are controversial. I mostly publish my answer to the question as a blog post. So in order to be eligible for a blog, I make sure that I can write at least a minimum of 400 - 700 words for a blog. If I find question that will not make me feel interesting to write, I usually skip those questions. If I choose such questions, I easily get exhausted with contents and my answers will not be long enough or worth it.
Coming to the upvote part, I don't upvote the questions usually. But your question makes me think that I should be updating at least the questions that I answer. I will look forward to do it in the future. But I do upvote some of the answers that are really making sense and favourite to me. By nature I'm attracted towards sensible question and answers that are quite elaborate. Just one sentence answer or one word answers will not really grab my attention.
Sometimes that topic that I choose may not be really interesting for other users. In most of the cases I look forward to answer questions that has got no answers in it. I completely ignore questions that are repetitive and the ones that already has so many sensible answers in it. Before I write an answer to a question, I read the existing answers and make sure I'm not repeating the same answer again in a different word structure. There is no point in saying the same points in my answer which some other user would have already mentioned. But at the same time, if an elaborate explanation is need, I don't hesitate to provide the same answer in an elaborate manner.
After many breakup and make up. After reading so many books and article on relationship. After experiencing both online and offline dating. After so many tears and failure. I think am strong enough to settle questions that has to do with relationship and I like such questions the most. Though am not married to have a deeper knowledge on this field but I believe my experience is enough to impact someone on how to make the right decision when it comes to "selecting a partner, having a long lasting relationship, handling a nagging girlfriend, how to deal with long distance relationship, how to notice attention drift, how to know someone is cheating, how to make relationship memorable etc.
So when relationship aspects are address, I think I talk good on such aspects though not perfectly but I can be of great help on such field.
And I upvote some questions that comes in such field though my little steem power doesn't add much value or payout to the person asking the question
I always love crypto and blockchain questions. and Yes, i upvote it and answer it because i love cryptos and blockchain.
I love question about life. It will give me motivation to survive and not giving up to face problems in my live.
Of course, I will vote them
Well as a matter of fact I like questions which I can answer to and those as well where I can learn something from the answers of those questions that I do not know the answer to.
It could be anything informative and something useful that I can give my time to in answer and if there are already answers provided I would sure get to know what I can get from those answers.
As for Upvoting questions I do upvote them and the ones that I answer or the ones that makes the time worth it reading for.
While yeah we all have different taste so the choosing of topic should sure be different as well.