Increasing milk supply?

Right now I’m able to pump about 3-4oz in a sitting. I’m pumping and bottle feeding (for the most part), it makes me feel better to see exactly how much milk I’m able to produce/feed my son. He’s fed every 2-4 hours, which is how often I pump as well. Just wondering how much milk you other mamas are able to produce, and what advice you have for increasing your supply? I’d love to have a freezer stock for when he’s baby sit/I go back to work in a month. Thank you! 🙏🏼