One way to find a good cosmetic dentist is to check with local chapters of dental societies, dental schools, and other types of dentists. However, don't neglect your own circle of friends and family -- networking with them can often get you some good recommendations.
When considering a prospective cosmetic dentist, be sure to check the costs, benefits, and risks of each of their alternate treatment plans. In addition, ask them about the life expectancy of the work they'll be doing, and what kinds of guarantees they offer.
Before committing to cosmetic dentistry, do some research on how much tooth reduction the proposed procedure will require. Some procedures, like capping, and result in extensive reduction, sometimes leaving too little original tooth material for later cosmetic work.
