According to this article, it takes more than just frustration with your current situation or a bucket of money to throw at the problem.
"You see it in professional spin-offs all the time… Two or three key architects in an established firm leave with a few clients, just knowing they can do it better on their own. But then they go out and start a company that’s cut from the exact same cloth as the last place they worked. They use the same accounting software, the same processes, the same fee structure, and even the same spiel in their pitches. The only thing that’s changed is the location and the letterhead."
Author Michael Gerber, in his book "The E-Myth," tackles this problem head on.
If you are looking for a holiday gift for a lawyer with a branding issue, consider this easy to read, but thought provoking book.