I use the built-in shipping function in Shopify rather than a separate app. I'm in the USA and always use USPS as they are the most convenient, is almost always the least expensive and despite recent changes and rumors, I almost always get good, reliable service.
I've noticed lately at fulfillment, Shopify is defaulting me to UPS rather than USPS and since I'm almost always in a hurry, I don't notice until I've printed out the shipping label. So then I have to go back to void the label and repurchase it. I'd love it if there was a way to set a preference to default to one particular shipper so I don't have to go through this. I've been searching for it because it seems like a no-brainer, but can't find this functionality. Am I missing something?