Abstract: A dental tray molding kit and method include a moldable generic tray and a thermoformable material removably insertable in the moldable tray and biteable by a user upon placement of the thermoformable material inserted into the moldable tray in a mouth of the user. Another dental tray molding kit includes a rigid generic tray; an impression material removably insertable in the rigid tray and biteable by a user upon placement of the impression material inserted into the rigid tray in a mouth of the user to create an impression tray; and a thermoformable material removably insertable in the impression tray and biteable by the user upon placement of the thermoformable material inserted into the impression tray in the mouth. The kits can be configured to whiten teeth of the user as a cosmetic procedure.