Good questions, Melissa.

When I give someone a pos rep for something, I don't expect to hear anything back from them. And except for one or two rare exceptions, I never do. I'm also not in the habit of acknowledging every rep point I receive. Not that I couldn't say something to someone, if the comment or post in question happened to spark conversation...but I don't feel obligated to do so, just as I don't expect anyone else to.

As for other tips...I'd say that when leaving a negative rep for someone, to consider it carefully. If you truly feel they've been disrespectful or offered bad advice, then make your mark and try to leave a message that will show them WHY you left it. But if you're just irked at them because of disagreement, or you just don't care for their "tone of voice"....those aren't good reasons to leave a neg rep, in my opinion.

And even when leaving a pos rep...I try to leave a note that lets the person know why I liked their post.