For years my workflow on a remote box had a single point of failure: the SSH connection. The train goes through a tunnel, the wifi sulks, the laptop lid closes, and whatever long-running thing I was babysitting dies with the shell. I lost a four-hour migration to a flaky hotel network once. Once was enough.
tmux fixes this cleanly. The session lives on the server, not in your terminal. SSH in, run tmux, do your work. When the connection drops, the session keeps running. Reconnect and tmux attach, and you're exactly where you left off, scrollback and all. The first thing I now type on any new server is tmux. Not occasionally. Always.
The default keybindings are a little awkward, so two lines in ~/.tmux.conf earn their keep:
set -g mouse on
set -g history-limit 50000
Mouse on lets me scroll and resize panes like a normal human, and a bigger history means I stop losing the output I actually wanted. That's the whole setup. Everything else is gravy you can learn later.
If you run anything important over SSH and you're not in a multiplexer, you are one dropped connection away from a bad afternoon. Run tmux. That's the note.