Great topic choice @yoyojoe! Tooting my own horn here… 
I have been low-key selling these holsters here on the forum for a few months now and people have been enjoying them.
FS: The Bear Hug: A handmade tailor-fit holster for the Ti-Vayder yoyo (fits most modern yoyos)
Also designed these leather yoyo pouches a few years back. - I have never sold them because I hand-stitch them and they are likely too labour-intensive to price reasonably. I posted this tutorial a few years ago on how to make one - for those interested (the image is the link). If you have any questions, feel free to contact me!
https://imgur.com/gallery/1N8rk
edit: I have always had an obsession with EDC and carrying solutions. I spend a lot of time designing carry-cases for all of my hobby/life items. Who else is this into cases/EDC solutions?
Edit edit: most recent iteration of the leather pouch design: