I also use Endicia, with Galaxy Ship. I have the premium plan (or whatever its called - stealth postage, and bulk scan to name a few.)
My shopping cart is hooked up with something called Shipper. So I push a button to download all shipments and all receipts are printed out, packing list sorted alphabetically by my warehouse aisles. Then the shipper pushes the cart up and down the aisles, loads up the packages and then the combination of Shipper, Galaxy Ship/Dazzle all work together with my Zebra thermal printer (4x6 labels).
I type in the order number and everything is done, from selecting the correct postal carrier, to sending out the email, updating the customer order as shipped with tracking info, print the label, etc...
At the end of the day, we print out a Bulk Scan to bring to the post office so all packages are scanned in a second. (So customer knows they made it to the post office.) The shipping labels have my logo on them, and the Delivery Confirmation numbers so I know when they're delivered.
It's so very easy and fast, it makes shipping an almost joyful job!