IncludeOptional /path/to/conf/*.conf

<VirtualHost *:80>
    ServerName                  example.net
    Redirect permanent /        https://example.net/
</VirtualHost>

<VirtualHost *:80>
    ServerName                  sub.example2.com
etc...

*:443                  example.net (/path/to/conf/example.net.conf:6)
*:80                   is a NameVirtualHost
     default server example.net (/path/to/conf/example.net.conf:1)
     port 80 namevhost example.net (/path/to/conf/example.net.conf:1)
     port 80 namevhost sub.example2.com (/path/to/conf/sub.example2.com.conf:1)