How do I value a service business, like consulting, coaching or a legal practice?

A service business where all revenue is generated by the owner’s expertise and services may not have an inherent value to be divided in the property division of a divorce.  There may be some equipment, like a computer or office furniture, that could be valued and bought out in the divorce.  But the income earned by the business owner by providing service may alternatively be considered income in the cash flow analysis.