Best practices for modifying plugins, themes, etc

Hi, I'd like to know how we should go about modifying files inside "plugins" and "themes" and omeka core files so to not have any problems when updating in the future... thanks.

When modifying a theme, it's usually best make an entirely new copy of the theme (make a copy of the whole theme's folder and give it a different name). This way, even if you update the theme you were working on, you won't lose your customizations.

Plugins are a little trickier, because many of them rely on the folder to have a particular name.

Of course, it's always wise to keep a backup copy of your Omeka site, including plugins and themes, before you update. Even if you accidentally overwrite your work on a plugin or theme file, you'll have the pre-upgrade copy to work from.