i have the same problem, but mine specifically is that i dilly-dally in the mornings. deciding what to make for lunch, then making it, etc takes up too much time, and then i'm REALLY running behind!
finally got smart and started making things like big pots of soups, stews, curries, chili, etc and freezing them in individual portions. i just grab one out of the freezer in the mornings, and ta da! lunch! the bonus is, they defrost by lunch, and stay cool all morning, so refrigeration isn't really an issue if you don't have access to one.
i also started making crockpots of sauces, and then freezing portions of sauce in muffin tins. i make a single serving of pasta, one "muffin tin" of sauce is the perfect size and voila! no fuss pasta.
i also buy mini pita breads and freeze those, too, and just pop them out of the freezer to make egg salad sandwiches or tuna salad sandwiches when i'm in a rush.
i also made some muffins and froze them in big containers, so that as i head out the door i grab a few of those too for breakfast once i get to work.
if i didn't do it this way i would spend an unholy amount of money on takeaway. it makes making lunches so easy, i don't even have to think about it anymore! hth