Look just above this paragraph and tell me what you see. . . I bet it is a thin straight line, right? That's an HTML tool known as a Horizontal Rule (coded as <HR> when using it on your web page)
Now there are several cool aspects to Horizontal Rules: first is that they introduce a full line break in whatever you're typing. Second is that you can play around with them (this is a trick I learned from Lynda Weinman.
Make your separator a small interruption in the page: Just add a WIDTH tag, for example <HR WIDTH="20"> and you've got a small, smart rule!
Try other experiments with your <HR> coding. A narrow separator at the left margin can be a great effect: