This is how I store sanding disks, in PVC pipe end caps.
They are in a drawer so they stay clean of chips and sawdust. And Velcro-up so I can pick them up one at a time using the mandrel on my sander.
I don’t rely on the PVC to align the disk on the mandrel. I haven’t had any problems aligning the disks by hand.
I use 2″ hook-and-loop sanding disks. I added a strip of sticky-backed velcro to the edge of a shelf to hold the disks between sandings. They stay convenient, clean, and organized.
I use small, cheap die grinders from Harbor Freight for inertia sanding. They are small and cost about $10 when on sale. They may not be great die grinders, but the bearings are good and they have a 1/4″ collet that accepts my 2″ hook-and-loop pads.
Inertia sanding is when you hold a sanding disk to the wood while it’s spinning on the lathe. The turning wood spins the sanding disk so you don’t get straight scratches. It’s less aggressive than power-sanding, and can produce a better finish than plain flat sandpaper.