So the biggest answer is to find one that match your situation and apply it.
If you are using debian distro deriatives.,the solutions are usually just a couple of steps,so if you are going to do major changes backup or copy the original and finally document all your changes (use a flowchart or mindmap) so you can reverse everything
Take for instant I have 4 server on one machine ,I used both Multiple IP with Multiple Port.
What I do is try and set the virtual host then move to the directive.
search also the forum for Virtual Hosting
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