You can’t do this before you have the baby, but when you’re ready to start pumping, measure your nipples to make sure you’re using the right size flanges. I had terrible output with my first child because I had no idea how the flange was supposed to fit. It should only be a couple millimeters larger than your nipple. There are free downloadable rulers on sites like genuinelactation.com

Have a nipple shield just in case. Even if the kid can latch well it can give your nipples a break as they’re getting used to nursing.