While kiteboarding already has a huge lightwind advantage over sports like windsurfing, everyone always wants to get the most riding time possible. For most kiteboarders on a standard setup (12m Kite &140cm board for 175lb rider) rideable wind begins at about 15 mph. This amount of wind is apparent because whitecaps become easily seen and prevalent on the water around 15 mph. With this same setup jumping and powered riding will begin at around 17 mph.
One of the best things you can do to improve your lightwind riding is to become a better kite flyer. Accomplished kite flyers can lose as much as 3 mph of wind and still be riding because they keep the kite moving in the power zone. A good way to become a better kite flyer is simply flying in light-winds. You can learn more in an hour of flying your kite in sub 12 winds than all your previous experience combined. It is much more difficult to fly the kite in these winds and it is necessary to keep the kite moving.
Remember to pull in for more power when turning, then let the bar out to allow the kite to become more aerodynamic and rise in the sky.