One size does not fill all, especially when it comes to earbuds and phone cases. Here are two mods you might find helpful- the first adds a lightweight and comfortable ear hook to those squirrelly Air Pods, and the second prevents a phone's belt holster from slipping off.

Air Pods occasionally leap out of your ear canal and into the aether, never to been seen again. A detachable "hook" that fits over over the outside (or inside) of your ear can help, but the airpod must be easy to install and remove since the hook won't fit in the charging case. I prefer the over-the-ear design, but these are often constructed from urethane or silicone rubber. Both of which attract dirt and absorb skin oil. Plus get a little sweaty in the summer.

So I modified a commercial earhook made by gcoiioi. They overmold silicon rubber onto a nitinol wire- the wire is particularly springy and will not kink. Superelastic. Just run an x-acto knife under the rubber and parallel to the wire to remove, and you go from:

to this:

Lightweight, clean, comfortable and highly functional!

As to phone cases, I prefer a belt holster. Compared to slipping a phone in your back pocket, a holster keeps lint out of the charging connector, is secure, the screen never scratches, and there is no possibility of butt dialing. Though definitely not a fashion statement...

But there is a problem with most holsters- they are easy to clip over your belt, but when you sit down your leg can lever up the holster and spring open the clip. Then when you stand up, the holster drops with a dull clunk on the floor. Or silently escapes from your control.

I 3D printed this little hasp:

and glued it onto the back of my holster. A tab cantilevers over the belt clip so it can only spring open when the clip is rotated 45 degrees from the centerline.

While wearing your pants, just slide the clip over your belt:

Rotate the holster 45 degrees and the clip is locked in place.

Problem solved!