A big break through I had in enjoyment of sessions is to slow down and get organised when starting after a crash.
Make sure the leashes are not tangled or wrapped around the foil.
Make sure the waist belt is spun around so that it hangs in the right position.
Make sure the leash is not between my legs (or stuck between my toes

).
Get sorted and go.
Even then, watch for waves or gusts or anything that will get in the way when you're trying to start off.
None of these things are session ending, but anything that detracts from riding and having fun is a pain.
As for leashless, on the Blue Planet interview Gunnar couldn't show any boards because 3 of them were off being repaired after ending up on the reef. He said it's the price of riding leashless.
I use a waist leash from One,
www.oneoceansportsaustralia.com/accessories/no-logo-waist-leashIt works fine. I removed the little carabiner because it put a tiny surface scratch on my board. I grabbed the velcro end off a Balin leash and that fits nicely. It's very easy to mix and match leashes and belts and swivel ends and stuff to customise your leash.
I tried using a vey long coiled leash to avoid the upside down foil of death situation. The long leash did not help because the board did not stream out to the end of the leash. It flipped and ended upside down upwind of me.
Flipping seems to happen less with more experience in strong winds and I have found lying on top of the wing stops it trying to impale itself on the foil and leaves my hands and legs free to fend off the foil. I lay my body across the leading edge in kite self rescue position so there's no real risk of bagging out the wing.