An analogy....... Occy straps are now banned at any hardware store when carrying a load.
Learn to body drag. When teaching I always did body-dragging with a board. If you havent done this as a beginner you should. Get set, and get someone to put the board 10m upwind of you. Go one way, slowly as high upwind as you can go. Use your hand in the water as a rudder and lie as flat as you can. Count to 5 and try to catch a glimpse of the board. wait another 2-3 seconds and slowly bring the kite to 12. Change direction and repeat the process. Within 3 tacks you should be back at your board. If your not, do it again.
Repeat at 20m, it should take you 4-5 small, SLOW upwind tacks. If your riding powered, depower your kite, going fast means going down-wind.
This is not done in just about every lesson Ive witnessed, yet is essential before jumping on a board.

Like turtle hunter said, he used a leash AFTER 8 years of kitesurfing. I use one at reefbreaks, or where there are swimmers/surfers in the water. It is dangerous, twice Ive had the legrope wrapped around the bar/lines.
Most good surfing legropes have a tab/loop to lift it off the velcro. Tie a piece of rope, it helps for a quick release.
In flat water????? Do what I wrote above and any beginner would feel different about the zimmerframe