There are two ways to create a Shift Template. The first method is to save an existing shift into a template. The second way is from the "Manage Shift Template" menu.
Once created, templates can be used to create a shift with one-click in the scheduler.
A - Create a Shift Template from an existing shift
Click on an existing shift to open it
Save it as a template
You should name it before you save to find it with more ease later
B - Creating a template from the Shift Template menu
Go in "More" on the top right of the agenda
Manage Shift Templates
Add a shift template
Set your criteria
The template will now be available for the quick shift creation in the scheduler. It is also from this menu that you will be able to edit Shift Templates.