Women are far more likely to be willing to have sex with you if they feel like there is a mental or emotional connection on some level.  Some women are looking for someone to challenge them intellectually.  Some women are looking for someone who has the same desires, tastes, and wishes as them.  Some women are looking for the opposite, a perfect compliment to their desires, etc.

The key is conversation and communication.  If you can engage in an intelligent conversation with a woman, you will find out what interests her, and what her desires are.  I don't mean you should just listen for certain key things, and parrot back to her what she says.  Truly listen, and truly communicate what your desires and thoughts are.  Trust me, more times than not, if you are not sincere, women will see right through it.

Be yourself, and communicate openly, and the doors will begin to open to something more.  As the two of you talk, you may both find out that you have more in common than you ever thought.  You may also find out that you have very little in common, or that your desires suit you better to be friends rather than lovers.  Sometimes this is the case, and you count yourself lucky that you have found a new friend. But if the opposite is true, if the relationship moves on the next level, the sex between the two of you will be so much more incredible if you have connected on a mental level.  

Having an open line of communication can enhance a sexual relationship more than anything else, more than any sex toys, new positions, role-playing, etc.  It allows the two of you to enjoy the moment so much more, and may also bring on the added benefit of being great friends as well as lovers.  So, stroke that most important organ, and you will find the benefits to be greater than you ever could have imagined.