Heat sterilization is best but many states allow for chemical sterilization provided that the tools are soaked for at least ten minutes between customers.
You can tell a great deal about a salon by the quality of the products they use. Do the polishes look new or like they have been refilled a couple times. Are the labels in good shape and the polish in good condition? Have you heard of the brands they use. Are there a wide variety of shades available?
Do you like the idea of a full service salon that offers waxing, and other spa type services? Other services carry other licensing requirements. Be sure that your tech is licensed to perform the services he is providing.
Technicians will try to up sell. Would you like a design? Do you need your brows waxed? Be sure you know what the charges for these additional services will be.