Alongside project templates, you can create item templates within the same File – Export Template wizard. I won’t spend too much time here as much of this information is repeat from how project templates work.
Instead of choosing Project Template, choose Item Template in step 1 of the wizard.
On the second page, you’ll choose which file to create as the template
Then you can specify which references to include for that file.
And the rest are similar to the Project Templates, where they live, what customization options there are.