Every expert is self-proclaimed. There are certifications that will ensure a client or employer of your knowledge but nothing compares to the proof of your skill like having previous (and current) success. Personally I roll my eyes at most so called SEO Experts. In my former job I've delt with many companies that offered SEO Services and rarely have I ever come across an SEO Expert that had more than mediocre education and experience on improving the traffic to your web site. Most "SEO Experts" will stuff keywords with a non-readable format, submit to directories, and advise you to partake in PPC. Some may even help you with your HTML formatting and proper title and heading structures. Basically....there is no such thing as an SEO Expert. I'll let you assign such a title to yourself once you show me a web site you took from 0 traffic to thousands per day.