very loosely moving the towpoints toward the centre will have that effect but any bridle change has lots of consequences so while it might turn quicker for a smaller input you will probably find your backspins suffer for example.
Make your changes in small increments and whenever you try a change always measure and mark original positions so you can return to original settings when you don't like what you've done.
To see if you like the feel of moving the towpoints in try just tying a temporary knot in your inhauls to shorten them.
This just scratches the surface of bridling trys to describe the changes in feel you get with different adjustments
http://www.iannewham.com/kitedesign/bridling.htmland no discussion on bridles is complete without a link here
http://www.andywardley.com/kites/bridle/index.html
