I think you need to ask about what you are slicing. A good edge for meat is not a good edge for shaving or wood carving.

The first check for me is if it looks sharp.
If you look at the edge straight on with the light behind you a full edge will reflect a line of light while a sharp edge reflects no light.
Then I see how it cuts. For woodworking any dull spots on the blade show up on the cut surface of the wood.
They kind of go together. When the blade loses its bite it needs sharpening.

Other than that I don't really check edges except by using them.

Edit: I have been known to shave a bit of hair off my arm as a check while it am putting a fine edge on, but that is just the carving chisels and my razor.
I don't think a kitchen knife needs to be stropped and having a bit of tooth to the edge lets it slice meat and tomatoes better.