Simply ask to see their certificate. Certified lash artists should be able to provide you with their certificates as well as the name and contact information of the institution where they were certified. They should also be able to show: - Before and after photos of their work. Certified lash artists will usually have a portfolio that they can show you upon request. - A list of the products they use and where you can purchase them. - References upon request. - A list of the lash extension courses they have taken. - A list of the lash competitions they have participated in.