Doug,
My experience, only .. and just nicely getting going (have decided I hate lenders, so taking new direction.)
Had done some legal work (actually non-appraisal) and gotten to know 2-3 attorneys. Am getting 2-3 estate appraisals, now (per month) plus 1-2 matrimonial. Not yet a living, but full fee and no arguments about values! That, plus tax assessment grievance (highly seasonal) can make a living .. but remember that most start-ups take three years to fully blossom. Each matrimonial gives you exposure to another attorney, so it's an exponential exposure ..
Insure that you point out that testimony is 'per-hour' with minimum of half-day billing for additional preparation.
Finally, with the matrimonials have begun developing 'business analysis' work as well as valuation of business by cash-flow analysis of the tax return. To me that's fun .. and dovetails with years of income tax preparation work.
Bottom line is others have to talk about you and build your reputation. If you come through the door and tell someone you're a hero, it's just sales BS .. but if one attorney mentions you to another, or to a client .. it's absolute fact and golden! Good, constant networking is the answer ..
Good Luck!