Cool trick and a well made tutorial. If I may add a criticism though some of the text doesn’t stay on long enough for me (probably others?) to read it. Of course it could be paused to read but I thought I’d to point that out for you.
Great start!
Try to find a space with a darker wall or tape up a sheet (I’ve even seen people use plastic garbage bags). Everything you can do to improve string visibility. Remember you want any light sources to be behind the camera, pointed at you. The more the better, outdoors of course is where you’ll get the best lighting. A 2nd angle doesn’t hurt either.
I’ve seen a couple of yours before. I really like them.
The ones at rethinkyoyo.com are really cool too. I’ve seen most of them already.
Pretty soon I think I might start making a series of videos dedicated to green triangles. Just different ways to get in them. I’ve just been experimenting with them a lot lately. I might even make one tonight if I’m not doing anything.