So glad to hear that you've gotten to this pain-free point!
To build up a stash for baby-free outings, start by pumping once a day. Most moms have the most extra milk early in the morning, so try pumping right after the first a.m. nursing session. Doing this once, or doing it erratically, won't get you anywhere. When you're trying to boost supply, you need to be patient and consistent, pumping at the same time every day. That will signal your body that demand is extra intense during that time interval, and should eventually result in additional supply.
You can try the herbal supply boosters like fenugreek and oatmeal, but please be aware that when it comes to increasing supply, nothing is as effective as increasing demand either by nursing more or by pumping.
Coolest thing my big girl said recently: "How can you tell the world is moving when you are standing on it?"
Coolest thing my little girl sang recently: "I love dat one-two pupples!"