more attention to basic hygiene (washing hands for example). before this outbreak, despite it being what you taught kids, not everyone washed their hands when they went to the toilet, and that's gross! (maybe now they will.)

maybe a rise in use of video chat services

less crowds at the supermarket?. maybe people will realise that actually, we don't need to go as regular as we did

possibly a greater respect for people's space (you don't all need to cram yourself so close together on the train, for example)