How do you stay motivated when working from home?

I worked at the same company as a full timer for a long time. I left because I got bored. Now I'm a consultant, which is another way of saying I don't have a full time job, I work out of my home and somehow I'm making more money than I did before. I also like the diversity of working on different projects.

Sounds good, right? I THINK its good...and I want to keep doing it. But it gets REALLY hard sometimes to stay motivated, not to get lonely and to be productive when ANYONE in my family is around.

What are some tricks of the trade? I could really use the help.