Ask Lemmy

I use different things for different edges.
Most of my hard working tools end up with a convex edge, I like them better for chopping stuff like wood and asklemmy posters bones and its good durability doing so.
So that's either automotive sandpaper in various grits, or 3M's paperless abrasive sheets (easier on curvy stuff). Slap a thin foam sheet or two on your work surface, choose your paper grit, work it, change to a figer grit, repeat until happy.
What I like about those is they're huge and easily replaced. I've done flat edges with them too by simply not using the foam.

For more traditional flat edges, I've mostly been using a pair of DMT's dual sided butterfly thingies, so that's indeed 4 different grits. That's what I use because that's what I got ages ago and got used to them. They're ok. Nothing amazing, but it works and it's small enough to sit in the kitchen drawer.

I also have a fancy kit that clamps on the blade with a metal arm that keep the tiny stone a the same angle and whatnot but it's kinda annoying to setup.
It's probably more consistent than anything I do by hand, but I never bother using it because it's clunky.

In the end, whatever you actually use is gonna be better than anything that sits in storage.