Part of being an artist is knowing when to say "when" and learning how to edit. Not every work "works". There are pieces of mine that didn't seem to grow with time - they festered. There are also pieces that are missing something. I usually refer to that something as the "punch" (as in, "it doesn't have any punch"). Here are a few recent examples of works that have been sanded down and now only exist as digital images:
This fog painting was going ok as of last night but it won't do for the current show and I needed to make the tough decision to paint over it and re-use a good panel for something more powerful.
This was a brief sidetrack of several attempted drawings of sinkholes. I painted over this work and the next piece also was a failure. I think this piece of paper will end up with my pizza box in the dumpster.
These six lackluster works were also recently sanded down and one was painted over to be this: