What are some key behaviours for good etiquette in Japan?

A friend who will be travelling to Japan for the first time asked me this recently. I [tooltip title="was stumped" content="困惑した"]was stumped[/tooltip]. Eventually, I reassured him: “You’ll be fine! [tooltip title="After all" content="どっちみち"]After all[/tooltip], you don’t talk loudly in public. Perhaps just avoid talking on your