Template workflow
After you've enabled the templates module for a site, you can start creating and using templates on the site.
Who does what ultimately depends on your particular team and project. Keep in mind, though, that whereas creating a modification is purely about checking and defining options in a graphical user interface, creating a template involves writing code.
To create a modification that uses a template:
You can freely edit the template after creating it.
You can also check in which modifications the template is currently used and remove the template when you no longer need it.