Start with the boring stuff: bank, tax, accountant, insurance, professional associations, university admin.
Then try to knock off a few big-picture items each day.
Make lists of people to email about work, and get through as many as you can each day.
Network actively through acquaintances, friends and the Internet.
Drop everything and rearrange your plans because work has come in!
Make plans around the work, because, you know, you have a life, too.
Oh, wait, the work gets rearranged. Re-rearrange everything accordingly.
Return to original boring stuff, big-picture, emails and networking.
Is this frustrating? Initially, yes. But really, this is the test of How Things Work. I have learned, even on job number one, that being a freelancer requires a bit more adaptability than your average 9-5. This may seem startlingly obvious, but in practice, it has a lot more impact than you might expect.
Consider this: your friend's in town for the weekend, you had a night out planned on Friday and guests all of Saturday, followed by a nice literary event on Sunday afternoon. Well, think again. Now, rather than having a solid two days' work under my belt before the weekend ensues, I will have none. So where to get the extra 16 hours' work? Out of the time that I might have been relaxing next week. Besides, I'd rather relax with my friend from out of town, right? Right. So really, nothing lost.
Remember: you signed up to this lark so that you could organise your own time -- so organise it.