For services only I depend on, I have production-only. Since I can only inflict damage on myself, and can often work around problems.

For the XMPP server my friends and family also depend on, I have a dedicated nonprod VPS. My services are driven by ansible playbooks, so I’ll tweak the playbook with whatever change I want to make works in nonprod, before running the same playbook against prod.

Whenever there’s a new Debian Stable release, I’ll rebuild the machine completely, to try and prevent “drift” between the nonprod and prod versions (not that I change things often enough for this to become a big problem). This is also the big test of my backups, which so far haven’t been needed in a “real” emergency 🤞