I went to a book sale the other day and nabbed a copy of How to Write by Stephen Leacock. Leacock was, in the early Twentieth Century, the best-known humorist in the English language. Which fact should give all humorists pause.
I more or less know how to write, but I'm always ready to learn something new. So I went trawling through the book. Mostly, it's plodding and sincere. Out of insecurity, Leacock didn't get serious about writing until he was 40 and he regretted that. So he's on the side of the gonnabe writer and explains things very carefully.
However, right in the middle of the book somewhere, he suggests the single most brutal test for a story or novel I've ever encountered. Here it is, in my paraphrase:
Remove a page from the middle of your work. Set it aside. Then read the page before it and the page after. Can you reconstruct what happened in that page? Then your work is mediocre at best.
This is not an exercise I'd recommend for not-yet-published authors. But it sets the standard, dunnit?