Schizo directed me to this post at Zen Habits on working from home. I've heard lots of tips like "Wear work clothes. Put on your shoes. Take breaks. Separate your office from the rest of your house." Here are some tips of my own (nothing novel I'm afraid):

1. Segment: When a project comes in, immediately review it and break it up. Know exactly how it will fit in, when you need to start it, the minimum amount of work you must do on which days to get it done early or on time.
2. Keep a calendar: Write down on each day what you need to do and keep the calendar right in front of you at your desk. Make due dates clear.
3. Keep a list: I keep a list separate from the calendar. I write down the stats of each project, the contact name, the due date, the size of the job. I update the status of each and then cross each off when I am done. Where the calendar lets me see across time, this list helps me understand the amount I have pending so I don't get overwhelmed.
4. Get up early: When I don't get started early in the morning, I suffer from a loss of drive by the time lunch rolls around. If I can get a good start, my afternoon is more productive because I feel better about myself and my accomplishment for the day.
5. Develop a system: I won't say the typical "Stay organized!" because that rubs me like a "Have a nice day!" but I do think everyone needs his or her own system. I have folders for each client's style sheets/guidelines and a folder for each journal so I can grab the right folder when the project comes in. I have an invoice folder and I track what is out, what was paid, how much I make. I keep my electronic folders organized by client, project, due date so they are easy to find. When I am done, I move files to "Completed" folders to keep everything separate. Whatever works for you.
6. Resist temptation to get off task: I browse as soon as I turn on my system; I read the pages I normally read and get that out of the way right at the start. Then I (usually) check my browser only to see if email came in on my business account. I don't keep the TV on for company, and I put on the headphones if I really need to get focused. Do whatever helps you fight distraction.
7. Make shortcuts: In Word, I made a toolbar full of any button I might need for editing. I have two typed sheets of words from the MW dictionary that I always need to check, eliminating my need to repeatedly look them up. I created macros that insert queries I always need to ask. Saving time on basic tasks gives me more time to focus on making the projects perfect.
8. Be realistic: I know that unless I have a real rush job, I have had it by 8 p.m. I know I need to leave time for the gym, for an afternoon lunch with friends, for errands. Keep a schedule loose to accommodate for what you know you need. This also applies to starting and running a freelance business: Be realistic. Will you be able to focus, drive yourself to get things done, multitask without a boss hanging over you? I have many friends who tell me "I could never do what you do" and I believe them!