How do I insert a new line between two lines (products being purchased) on an invoice with the new templates?

Welcome to the QuickBooks Community, @00cyclone. I understand the importance of being able to insert a line item between existing items on an invoice in QuickBooks Online (QBO).

With the new invoice interface, the feature to insert a line item between existing items is not currently available. The hand icon that you mentioned is indeed used for dragging existing line items to rearrange them, but it does not allow for the insertion of a new line item.

The new invoice interface does not currently offer the ability to insert a line item between existing items. While the hand icon you mentioned is used for rearranging existing line items, there is no way to use it to insert a new line item at this time.

Here are the steps to follow in the new invoice experience:

1. Click the Add product or service button. 
2. Hover your mouse in the very first column or over the 6 dots icon. 
3. Drag the new line to move it in between the two existing lines where you want to insert it.

For visual reference, refer to the screenshot that I've attached below.

For more information regarding the new layout of the invoice, you can refer to these articles:

• See what's new with estimates and invoices in QuickBooks Online
• QuickBooks Invoices and Estimates FAQs

Additionally, I've added this link about personalizing sales transactions in QuickBooks: Customize invoices, estimates, and sales receipts.

If you have any questions about invoices or need help with other QBO features, please let me know by replying below. I am here to assist you. Have a great day!