I have found that you have better success when approaching women when you actually have something of value to offer. It's not just about getting numbers. Are you funny? Are you interesting? Are you going to make her life better? Also, women have standards. So should you.
Yes, be honest about what you want. But remember, the point is not sex. The point is love. Great sex is the result of love. That has been my experience.
The first rule -- I am learning -- is love. You do not go up to women or approach them with a mentality to get something from them, to use them. You do this because you love women. That is the first mentality.