In February I started a time-travel story for the Time in a Bottle anthology. It took me a whole month, but I finished it a little over a week ago--and it was way too long. So I took a machete to it, and managed to carve it down to just under the maximum wordcount yesterday.
But I still wasn't happy with it, so I decided to sit on it another day. And last night just before I fell asleep, I realized what the problem was. An entire scene was completely unnecessary--and I'd known it on some level because I'd been whittling away at the scene until it was really just a nub of its former self. Today at lunch I whacked the scene out completely.
But I decided to hold off on sending it out until I could give the whole story one last read-through and make sure I hadn't left any references to the deleted scene. And as I read this evening, I had another lovely realization, that I needed a short exchange between the two main characters at the very end, something to tie together the story's themes. So I added that, and it worked. And I sent it off.
Watch it get rejected now, after all that work.