Begin or continue your course of study to become an expert. But tell your clients that you are now accepting business valuation engagements. Most valuation experts became experts through experience. Start getting yours right now.
Business valuation is a very subjective area.
This is perhaps the most important step. Realize that you can develop the skills to do business valuations just as well, and probably better than anyone else. It isn't necessary to have a certificate by an organization to be a business valuation expert. Don't be afraid to tell your client that you can do his or her business valuation. Business valuation is a very subjective area where judgment is the most important factor.