Research from 2020 has shown people can communicate better with cats by smiling at them more. But not in the human tooth-baring way but the cat way, by narrowing your eyes and blinking slowly.
The study results showed that cats are more likely to slow-blink at their humans after their humans have slow–blinked at them, compared to the no–interaction condition. It even worked for researchers with no previous interaction with study cats.
Source: ScienceAlert, May 26, 2023. Link.