You can create both folder and project components directly within the subcomponent section, you don't need to navigate to the Components section to create project components.
Creation of Folders
First, you need to click on the Create Folder button at the top right of the page.
After clicking the button a dialog for the new folder opens. Since folders do not have any attribute other than name and description, In the dialog that opens, you need to fill in the folder name and folder description. This will create a folder and immediately add it to the subcomponents list.
Creation of Real Components
You can create a real component from JIRA's own "Component" screen or directly inside the Subcomponents screen. To create a subcomponent inside Subcomponents screen press the Create Component button next to the "Create Folder" button.
A new dialog will be opened which allows you to enter component attributes. Other than component name all other attributes are optional.
Creating a component this way also adds this component to JIRA's own Component list. Even if you uninstall the add-on later the created component will remain. Actually this is a just shortcut for creating actual JIRA components. The new created component appears both in the Subcomponents page and in the JIRA itself.
