Click on the down arrow button next to "Add New Item" and click Add Masterlist Item
In the popup window, check the box next to the items you want to add to the quote
Click "Add to Quote"
Add a Master Line Item through the Quote
Once you have pulled up the Masterlist item popup (see instructions above), click "Create New"
Enter all of the relevant details for the line item and whether it is tied to airports, aircraft or aircraft types.