Comments. I have been changing my views on them. When I first started LJ, I never replied to comments left in my journal. Then I happened upon a journal-rating community, and one of their rating criteria was 'does this person reply to comments?' and that got me thinking. When people say something to you in real life, you don't just act as if you didn't hear them, so why do that on LJ? Nowadays I respond to almost all of the comments I receive, because even if I have nothing to say, it's just polite to let them know that I read their comment and appreciate it. I know I usually respond days later -- I think that's because I want to wait until people are finished commenting and then reply all at once so that I don't miss any.
Also, I want people to reply back to my comments on their posts -- if the comment is a decent length. If it's short, I don't care, but if I took the time to write out a few paragraphs and then don't get a response, I feel ignored. And then since I feel ignored I stop commenting. Why bother?
I also used to not comment much at all; I've been changing that, slowly. Why? Because I realized that even when someone left me a short comment, it mattered to me, so it probably matters to other people. And how do you know that I read your journal if I don't comment? Still, I don't have enough time to comment as much as I'd like. Mainly because I'm too much of a perfectionist... I save all the posts I want to comment to into organized temporary folders, and then go back and comment when I have time and inclination.
I get most excited when people comment on my jewelry posts. Really, really excited. So if you wanna show me love, comment on my jewelry posts. And do my polls. ;-)