I read something a while back that mentioned the writer's life and how hard it is to get motivated. With so many fun, family, and work parts of the pie that is a writer's life pulling us away from writing, slow forward motion can be a downer.
I don't have the answer, but I have tried a variety of methods to keep my writing moving. They usually depend on how close a deadline looms. But I've started giving myself credit for the writing I do in my head (some non-writers call this daydreaming).
I've found that if I don't allow a story enough time to percolate a bit and be mulled over, my time at the computer is not particularly productive. So give yourself a star! Count the standing in line at the bank, waiting for your engine oil to be changed, or being stuck in traffic as part of your writing process. You'll feel much more productive. It works for me!