The standard way is to set PS1 (the commandline prompt text) to indicate the environment. With escape codes, you can pretty trivially get some flashing red text telling you to be careful.
If used properly the -Confirm parameter in powershell can also have you change the impact level in your environment and ask for confirmation on things that in dev would not be cared about.
Also its underused but the just in time access stuff where you can grant users subsets of permissions (again, per environment) is also pretty impressive.
A not-so standard way is to output a banner via shrc (instead of putting it in the motd, which the ssh daemon will only output for interactive sessions) - which incidentally will also break pretty much all tools using SSH as a transport (scp, rsync, among others).
