The foolproof method:
Leave the kite in the bag. Take out the handles and unwind about 30cm of line. Work out which are the left lines and which are the right. Now the clever bit - STAND BETWEEN THE LEFT AND RIGHT SETS OF LINES... Now walk upwind, unwinding the line (holding the handles in the same hand they were wound on with. When you get to the end of the line you will be standing between the left and right lines (NO TWISTS!!!). Put a kite stake in the ground and rest the handles on it (Pulling on the brakes).
Walk back to the kite and take it out of the bag.
Fly!
When you pack it up do everything in reverse - fold the bridle lines into the kite and fold it up tight and neat. Go back and grab your handles and wind the line on nice and tight and neat. When you get to the bag, slide the handles in neatly on top of the kite, ready to take out again.
I've NEVER had a problem using this method. A little bit of time spent making sure everything is packed REALLY neatly saves a lot of time when you come to set up!!!