Send a thank-you note
Nyanue advises sending a thank-you email after the interview, but also sending a physical thank-you card. In a time when few people send these, this will make you stand out. Granted, during the COVID-19 pandemic, with many individuals working from home, this might not be an option, since you cannot (and should not) ask the interviewer for their home address. However, it’s possible their work is forwarding mail to their home now, in which case, you can send a note to their office. At the very least, it will be waiting on their desk when they return – it might be long after the job did (or didn’t) happen, but it will show your professionalism and keep you in their thoughts for future opportunities.