By nature, communication is important to most women. Why else do you think they would spend hours on the phone with their girlfriends and mothers? And in general, women are used to men being less interested in their ramblings. So, you want to know one of the best flirting techniques? Ask questions, and then actually listen to the answers.
Demonstrating an ability to listen in a genuinely interested way will drive you up the ranks -- and fast. Is she wearing a cool piece of jewelry? There may be an interesting story behind it. She'll know if you're faking it, though, so don't go overboard if the story isn't actually all that interesting. And do be careful of falling into the trap of the lovesick best friend. This means you may want to avoid lending an ear about anything related to current or past relationship troubles. This is the kind of stuff that lands you in the nice-guys-finish-last category.