When I first started to really think about food, it was around the time people first started wearing shirts with kale slogans on them. This was in the early aughts and well before the second-wave Beyoncé kale shirt. Dark leaves of Lacinato kale were always stuffed in my fridge at that time. I was eating them by the boatload in soups and sautés (Never smoothies, though — that's just a hot bitter mess, in my opinion).
I found the practice of washing them and prepping them very soothing, but sometimes it was a bit too drawn out for my taste. So when I came across this technique for removing the stem from the leaves, I was sold. It took my kale prep time down to a few minutes and I didn't even need a knife to do it.
Super-Quick Kale Prep Trick: Watch the Video
Squeeze and Strip
This is a technique you get faster at each time you do it. Start by squeezing the space where the leaves and kale stem meet to soften that fibrous connection. Then, holding the bottom of the stem firmly, run your fingers in the opposite direction along the stem, removing the leaves as you go. It's kind of like opening a zipper. I don't normally do this on a surface, although if you're just getting started this is a good way to go. Sometimes I'll even shape my pointer finger and thumb into a keyhole shape and strip the kale leaves from the stem even faster, but kale is tough and this can be a little uncomfortable.
Some tools mimic this motion, but if you can do it with your own two hands, why bother?