For the servers I own and manage, I'd chsh to Fish. That alone eased the whole sysadmin thing a lot.

But today, configuring a new server, I'm trying out a new approach: Don't chsh, but always SHELL=/usr/bin/fish tmux whenever I do stuff manually via SSH.

I'm expecting two advantages: Scripts that expect Bash will have less chance of breakage, and it will remind me to never start anything outside of Tmux.

So far this seems to be working.