Work: Work pants/shorts leg pocket.
Casual: I purchase smart/casual gear with 5 pockets...that small 5th pocket is where the case lives.
Formal: Haven't dressed formal in a while, but there'll be plenty of pockets to choose from. I'm thinking inner jacket pocket.
Sport/gym: In car's hidden compartment, which I'm regularly surveying during my workout.
In my drawer, all the time. I don't leave my house with them.
Here's a photo
https://imgur.com/a/8i9PO
That box was from the ATV 4.
I need one of those shock absorbers.