A dental tray molding kit for making a custom dental tray includes a generic tray, a thermoformable member removably insertable into the generic tray and a deformable spacer member placeable onto the thermoformable material and bitable by the user upon placement of the spacer member onto the thermoformable member in the user's mouth. The generic tray may be a rigid carrier tray and the kit may include a partially deformable member placed between the rigid carrier tray and the thermoformable member. A method for dental tray molding includes providing a generic tray, heating a thermoformable member until sufficiently pliable, placing the thermoformable member over the generic tray, placing a deformable spacer member over the thermoformable member, applying a biting force from a user onto the thermoformable member through the deformable spacer member, cooling the thermoformable member and separating the thermoformable member, whereby the thermoformable member forms a custom dental tray.
