Delegate Smaller Tasks
You rarely have to complete a work project alone. Maybe it's a department-wide project, or you have co-workers that are in-between projects who can help. Maybe you just have a few interns that are dying to stop making coffee and actually do some real work. Whatever the case, you should take advantage of every pair of hands at your disposal.
If you have access to someone who is especially good at some aspect of the project, don't be too proud to let them get it done. Have you been stuck creating the company newsletter every month? Ask a graphic designer to whip up a logo for you. Have the receptionist who works the front desk and knows everyone in the company by name collect wedding and birth announcements. The moral of the story: It's easier to get things done when you have help.