I have made various yoyo accessories over the years.
The first was a leather pouch:
I made my own nylon strings for a while.
I made and sold these holsters that I called Bear Hugs - including my own string pick design:
I will likely make these again some day.
And most recently I made the 3-Pack, the first product I sold under my lowkey brand Bear&Fox Armoury.
(Good news, I managed to find more stock cases in grey, so I will have another small run of these in the future - get at me if you want to reserve one 
).
Overall, I like to incorporate elements of outdoor gear, leather work and chainemaille in my designs.