Are you arranging opportunities for the student to practice writing thank you letters for a variety of situations?
Once the student has developed a thank you letter following one interview (real or simulated), does this mean that he can independently and appropriately draft another thank you letter following a different interview experience? Work to ensure that he can demonstrate how to use a general framework, while adjusting some of the content to align with that position.
Additionally, for a student more interested in personal thank you letters, offer opportunities for him to draft thank you letters to peers, instructors, or family members following holiday visits, after receiving gifts, or when someone has provided some helpful service or advice.
Have you adapted visual supports so that they can remain in the natural environments that this student encounters now, and in the future?
While the content of thank you letters will change due to the recipient, date, and purpose, the general format and rules of appropriate writing and delivery will be constant. Provide these rules on cue cards or as a reusable checklist. Additionally, provide the student with a template to support his independent development of thank you letters across generalized future contexts.