I'd welcome advice. Often when i try to execute a turn, I end up with the board more forward of the wind than the kite - causing the kite to stall. Any simple advice on how I can correct this. I'm fine with stopping and then restarting in the opposite directions - but I'd love to get turns sorted.
If you are talking about changing to toeside and carving round, it sounds like you might be taking your kite across to high in the window and then carving round as you do or even too early.
This will result in your kite not really being in much power and also across the other side of the window to you resulting in a loss of power. Then as you carve downwind a little and around at the same time, you end up further downwind than your kite and the kite stalls.
What you need to do is hop to toeside, then keeping your kite lower, pull on the bar fairly hard so that it stays lower in the window and turns more through the power of the wind window. Then once you feel the kite pull..... make the turn. Depending on how fast you turned the kite through the window, adjust the speed and arc of your turn keeping tension in the lines and constant power. If you turn directly towards the kite to soon, the lines will slacken and a loss of power will happen.
If you are talking about a slide turn. For example going to your right.... you need to slowly kill off your board speed by drifting the kite up to 1 whilst you edge a little against the kite killing off your forward speed. Then as the kite gets back up to 1ish, kill your last bit of board speed, change your footing and dive the kite back the other way. Timing is a factor here as you want to kill the final speed and change your footing just before you start to sink so that the kite doesn't need to water start you again but just pulls you in the other direction on the water.
If you take the kite all the way back up to 12, you'll effectively dive the kite back down the neutral side of the window on the other side resulting in little or no power. By only drifting up to 1ish, it will allow the kite to dip into a little power (like the water start set up) to get you going back the other way.
If you don't kill your speed off in your original direction, you will carry on a bit in that direction so when you send the kite back the other way, you'll be still going one way and the kite will be on the other side of the window resulting in a loss of power.
Hope this helps.
Once you get the hang of slide turns, you will find you can come in pretty quickly and edge a little to kill the initial speed before killing most of it at the very last second by edging hard (throwing some spray 
) and then changing your footing. You may find as you change your footing over, there is a moment when you have even pressure on both feet a bit like you are edging to stop on a snowboard on the hill. This will result in you skidding downwind a little as you change footing and send you kite but it means you can actually crank the turns and it feels GOOD!!! 
just follow the kite, simple. Turn the kite where u want to go and follow it. This way the kite is always moving ahead of u, and you will never find yourself in you stated predicament.
