Another interesting privacy option is Incognito keyboard. When entering text in clones it switches compatible keyboards into a private incognito mode where the typing history and personalized learning is disabled. Not all keyboard apps currently support this but Google Gboard and SwiftKey already do.
Officially the input method flag requires Android 8.0 or higher.
Below an example using a Gmail clone with Gboard, which shows the incognito image in the background behind the keys.