Very wise to use a staging environment. When you want to push your staging copy live you have to make sure that you have a backup of your acymailing tables as well as the /media/com_acym folder and the image folder in advance, so you can put these back in place after you have pushed the staging copy to the live environment. Same goes for any other files and tables that have changed on your live site during your development cycle like forms, user profiles, log files, e-commerce, etc.
The downside of doing everything manualy is that it is only a matter of time before forgetting something and losing data.
Some hosting companies offer staging features that offer you a standard and advanced push. The standard push is used to push the entire staging environment to live and the advanced push offers you possibilities to exclude/include database tables and files that you want to push live.
In case your hoster doesn't offer this you can have a look at this Joomla extension that ooffers these featurs: https://extensions.joomla.org/extension/stageit/ . It can save you a lot of time and hassle.