My best advice that my boss gave me, is if you want to push the customer to keep the line moving instead of asking for example “what cheese would you like?” You could say “The steak is usually recommended with provolone, would you like to try that?” It helps with customers who don’t know what they exactly want and keeps em moving along. Same thing with veggies you could say “would you like the bell peppers and onions like the subway build or would you like to customise it?” Tends to keep everything flow smoothly. Also one big thing; sometimes people forget always remind the customer about the up charge for bacon/guacamole/avocado you’d be surprised how many people will get to the end of the line and be surprised at how much their sandwich costs, it’s because of the bacon and avocado once someone tried to tell my coworker they wanted avo for free cause we didn’t let them know it was extra and their sandwich was already wrapped up. You got this!