Avoid monologues as much as possible. When you think you have anything interesting you like to share, finish it off with a question and leave the ball in her camp. Then think of what possible responses she could give to your question ahead and try to anticipate a possible remark to her response. That way you can keep the conversation interactive and you'll avoid her getting bored with you because you either engage in long monologues or you have too many pauses thinking of a reply or comment.
And like the previous poster also mentioned, humor is a powerful tool when used in flirting. I've seen women literally melt for a man who knew at what time to insert what witty remark (which made me quite jealous). It does require a lot of practice if it doesn't come natural to you, though, and I still fail in that area myself. I really need more practice

Humor seems to be attractive trait number one, but you know don't kick yourself to hard over it if you don't get it right at first.