1 Practice your recoveries on really short lines. You can just wrap the lines around your hands several times. Get within 30 feet of the kite.
2 Watch the kite and the lines from this position.
The Leading Edge Launch is the tougher of the 2 you've listed. You want the nose of the kite pointed away from the center of the wind window. If you can get the nose sliding forward, start trotting backward to gain speed to fly the launch. The rubbing of the kite on the ground eats up lots of energy.
The Cartwheel should be done with the nose pointed toward the center of the window. You want to tumble toward the center. You will pull (fairly quickly and a short distance) on the wing which is pointed up toward the sky. Give slack with the other hand. After the initial pull, quickly give slack so now both hands are holding slack line.
Watch what the kite is doing when you make your pulls and pushes.
There are many here more skilled than myself who can probably describe this better than I just did. Good luck.