First, you'll need to create a service for your Damage Waiver charges under Services in your Inventory. You can label this under "General Services".
Then,
Enter the Service information (you can also select the pricing structure - flat rate, percent of order, percent of line item group, etc).
Most vendors create a new Line Item Group called 'Services' in their projects where they would include all of the services for that project
You could just as easily add a Labor Service in the same Line Item Group as a Tent to show both your team and your client what the labor is being used for
Note: Multiple Damage Waivers or Services added to a project will not calculate their price off of each other.