Excellent guide!

What about using letsencrypt? It’s free and easy to install on nginx and apache

Wouldn’t that prevent the user from getting invalid certificate errors? And make it easy for people who don’t know a lot about configuring webservers (like me) to reduce time spent?

And a guide for apache web servers (if that’s possible, since apache is geared towards file system request rather than URI unlike nginx) would be very cool for apache users!