I upvote every submission that raises a point I'm interested in. As for the comments, I upvote both the ones I really agree with and the ones that contain some

I upvote every submission that raises a point I'm interested in. As for the comments, I upvote both the ones I really agree with and the ones that contain some interesting information I haven't heard before or interesting arguments. Apart from that, I frequently upvote downvoted comments.