So as I try to get better at sharpening, one of the problems I find myself encountering is the lack of a quick feedback loop. What I'd like to be able to do is sharpen up a knife, then test it somehow, and then either resharpen it or call it a day depending on whether it passes.
The internet is full of all sorts of folk tests: Shaving your arm hair, taking a curl off your thumbnail, slicing paper, cutting a tomato with no pressure, whatever. The internet is also full of people saying that some or all of those are silly tests that don't make sense for a kitchen knife.
So, my question in two parts:
1. How do you test that a knife is actually sharp when you're done sharpening it?
2. How do you do interim tests along the way, if you use multiple stones? That is, what convinces you that you've done a good job at the 1000 grit stone and are ready to move the knife up to a finer stone?