When I used to admin Windows servers we had production’s desktop background set to red, that worked well, especially when you had multiple remote desktop sessions open. Wonder if that’s doable for non-GUI enabled Linux servers
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.
Similarly, my prompt doesn't include the host when I'm logged in normally, adds it when I'm in a shell via sudo/doas, and colors it when I'm logged in via SSH.
Hasn't really been best practice in many workflows to connect to servers at all for a decade