I've enjoyed reading Patricia Wrede's blog about writing. Yes, she's talking about fiction writing, but some of her posts (how to keep organized, get over periods of ennui, etc.) can be useful to academic writers, as well. Her most recent post was one that shook me out of my complacency. She talks about people who write multiple manuscripts at once, particularly those of us (*cough* myself *cough*) who have a tendency to start in on fun, new projects, reach the first major hurdle, get bogged down, and decide to start something new. After all, we tell ourselves, as long as we're writing something, we're being productive, right? The problem is, we end up with more abandoned manuscripts than finished ones. Serious problem.
Wrede doesn't offer a solution, other than "cut it out!", but that's pretty much the advice I needed.