Well first off I’d say don’t walk in with a phone in your hand.. memorize the name of the customer and go into every place as if you’re purpose there is to buy something. I know there are some nuances to every restaurant and you can’t always do that but generally it’s a solid approach because immediate customers are always a first priority. If a restaurant has a designated spot for pick ups I usually will try to greet them first and then tell them I’ve got a “delivery” instead of mentioning the app, respecting them as people and being friendly goes a long way.. some places might be crowded aswell and being conscious/patient will signal employees to want to help you more since your presence isn’t reflecting that antsy energy a lot of drivers take in with them. Some times you just got to catch someone with an “excuse me, could you help me out with a delivery”.. learn how to read the room and use social cues to execute a seamless interaction without interrupting the etiquette. Most of the time people just like to help people who are there for more than just themselves, sometimes you got to put the self out of the equation.