For Joomla i use Akeba backup, nice and easy going commponent for backuping your site.
After install, go trough wizards, and they will make best configuration for your server. And you can manual sets another configuration if whant.
Then you backup your site, and download this on PC, after that you can upload to another server, and instal from akeba backup, similiar like Joomla instalation, no wory about database and so on. Or you can leave on your server backup, and instal whenewer you whant.
Best practice for me is to have, one copy of site on server, and one on my computer.