Range of motion and leverage are key in lighter winds. Hand position makes or breaks this. When the LE is facing up or down hands should be palms down. When the LE is facing left or right, the bottom wing hand should move to a 90 degree angle to the palm down top hand. LE facing right, right handle should be strait up and down, facing left the left handle should be strait up and down.
THIS IS ONLY MY EXPERIENCE SPEAKING
These handle positions stablize the kite. Meaning less or no wobble in the kite when inputs are given or hovers are held. This is based on the angle of the brake lines to the kite. Play with these hand positions next time your out and see if you agree.
As for tightening turns and 180's as Felix said and I have learned since he said it, accelerating or slowing one wing around the other adds to the precision of the turns.
On horizontal threads for instance, I've been taught to turn down on the 180 to return. That means the bottom wing initiates the turn. So push the top hand forward as you start the turn with the down hand.
Turning UP on the 180 is just the oppisit. The turn is started with the top hand and the bottom hand is pulled in as it rotates to the up position.
When flying horizontally across the window the top hand is pulled in slightly compared to the bottom wing. When you 180 your hands need to switch places. This is a bicycle thing

So, when turning up, give brake to the top wing, thumb to the bottom wing as you pull the bottom hand in. The quicker you pull the bottom wing in the MORE power your giving that wing. No power, the kite will drop slightly in altitude, just enough and you'll pivot around the logo, more than needed and the kite will rise in altitude.
This is something YOU as an idividual need to play with to figure out how much you need to give.
With the std. hand position in the beginning of this post you'll find that since the kite is stable your only really giving inputs to one hand when flying horizontally. Fly the bottom hand, the bottom hand is just there to keep the bottom wing in line with the top. Most noticable in reverse flight. Set your top hand in for your flight speed and hold it. Then adjust ONLY the bottom wing hand to keep it in line with the top wing.
More advanced (or maybe over thought) is flying two handed on all inputs. When you give brake for a turn, give equal amounts of thumb with the other hand. If you push one hand, pull the other equally. This effectivly shortens the inputs needed in half.
Give it a whirl. Tell me if I'm just thinking too much? I really wanna know. But try it before you tell me were to go.
Dean