One underrated — at least IMO — tmux feature are popups. For example, I have `Ctrl-a g` mapped to open a `gitu` [1] popup with a 90% window size. Once I'm done, the popup will just automatically close and I'm back at my regular terminal window.
[1] gitu is a pretty close approximation of Emacs' Magit as a CLI tool: https://github.com/altsem/gitu
