Maybe you already knew these. I didn't know most of them until I did one by accident.
- Open a message for reading in a new tab: Hold Ctrl while clicking the message
- Open a message for reading in a new window: Hold Shift while clicking the message
- Compose a new message in a new tab: Hold Ctrl while clicking the the Compose button
- Compose a new message in a new window: Hold Shift while clicking the the Compose button
Substitute Cmd for Ctrl if you're a Mac person, of course.
If you're a real
mouse hater keyboard fan, such that you're familiar with what j, k, and c do while you're in Gmail, you'll be happy to know that Shift-c, Ctrl-c, and Shift-Enter behave as you would expect. Sadly, Ctrl-Enter does not. But I'll reach for a mouse to get a clean read like this:
Gmail message opened in a new tab [ + ]