I'm fairly new to hosting with Digital Ocean. I only have about 3-4 sites up currently. I've ran into a few instances where if I misconfigure something or an update goes bad, it takes down all the sites. For example, I passed a bad argument to certbot when experimenting adding a subdomain to a site, and it misconfigured the SSL for the site and when I reset apache, all my sites had 500 server errors.
I was wondering what - if any - standards/procedures there were for minimizing downing all sites when a single configuration goes wrong. If I have a typo in a virtual host and I reset apache, I don't want every site to go down in error.
Is there a way to mitigate this so it only affects the site I am messing with? If that's not possible, what are some best practices to follow to not down every site on the server?