I always give an upvote to someone who answers my questions. I think they deserve it because they took their time to read it and share their opinion. The only time I don't upvote them is when they really don't answer it, when they say something that doesn't make sense or something rude.
as long as i like the answer and they actually answer the question, i will upvote it. they took the time to answer the question, the least i can do is show my appreciation. as far as upvoting other ppls opinions, if someone says something that i would have said, i'll upvote. OR if someone makes a really good point even if its the opposite of what i would have said, i'll upvote. i dont have to agree with the opinion for it to be a good one.
I mostly upvote everyone unless I /really/ didn't like what they said. I try to avoid upvoting everyone but I always appreciate opinions left on my questions so it's like a little thank you for answering!
I typically upvote anyone who answers my questions just to acknowledge that I've seen their response and give them a point for taking the time to answer. I don't upvote obvious trolling or rude answers.
I am not one of those people that just upvote everyone's opinion when I ask a question or view options to someone else's questions.
I upvote opinions that stand out to me, I agree with, took time and effort, or ones that are extremely funny when the time is right.
I do not just upvote opinions that are a sentence long it actually p*ssea me off. Unless that sentence is meaningful or the question is simple and there is nothing you can really say besides that.
I know you didn't ask but I also down vote. I won't down vote an opinion that's short but I won't up vote it either. I down vote opinions that I find rude/offensive, off topic/irrelevant, and of course it's main purpose one's I don't agree with. But I won't down vote to a question like what's your favorite color I mean how can I say I disagree what someone's favorite color is and that also p*sses me off when people do that because it just makes no since -_-