Not OP but I’ll suggest one that is very dear to me: make sure you use the same verbs for the same actions, the same nouns for the same things, the same proper nouns for the same important concepts. This alone removes a huge mental burden from users: it’s always “delete”, not sometimes “remove”, “cancel”, etc
I'm actually compiling a list of UI text mishaps, and I plan to publish it as a blog post at one point. A simple one would be to avoid using "your" in a "user -> UI" context (command), and "my" in a "UI -> user" context (message). For example, "Delete My Files" is okay on a button, but, in a message it must be "Are you sure you want to delete your files?". But, the better is to avoid generous use of "your" and "my" unless necessary to disambiguate.
For example, don't have a button that reads "Go to your profile", that screws up translations in languages like Turkish.