Thermoplastic sheets have become extremely popular for fabricating clear vacuum-formed orthodontic aligners and retainers. These appliances are preferred by patients due to their excellent aesthetics, ease of use and minimal discomfort. Although a single thermoplastic sheet is normally used to fabricate a single clear aligner or retainer, this clinical tip illustrates a judicious way to fabricate two retainers using a single, 1-mm-thick Duran thermoplastic sheet (Scheu Dental, Iserlohn, Germany). The two dental casts, either maxillary or mandibular, are orientated in a BIOSTAR model cup (Scheu Dental) in such a manner as to provide adequate distance between them, which results in stability of the casts along with uniform distribution of pressure during the pressure moulding process, both of which are required for optimal adaptation and accuracy. This modification to the manufacture of aligners and retainers is useful for fabricating any kind of clear thermoplastic appliance. This two-in-one approach to the fabrication of clear appliances optimises time, energy and effort, facilitates prudent use of resources and minimises waste, and thus can help to protect the environment by reducing use of plastic and laboratory costs. Keywords: aligner orthodontics, aligners, clear retainers, thermoplastic sheet