The single best way to increase milk supply is to increase demand. That means when you are home with baby, you're latching as often as possible, with as much skin-to-skin contact as possible.
And remember this - it's EXTREMELY common for babies to take small amounts of breastmilk while Mom is gone, and then cluster feed when she gets home. Generally speaking, the baby won't eat nearly as much away from you as she would when you were home.
While pumping, you want to be comfortable and as stress-free as possible. Don't look at the ounces while you're pumping. I know it's tough, but try not to think about the actual milk supply. Read a book, watch something on your phone. If necessary, put warm cloths on your breasts to encourage letdown and easier flow. Always keep in mind that for the vast majority of women, pumping gets about 25% of what you're actually producing. Which means that while what's in the bottles is less than usual, she's almost certainly more than making up for it when she nurses once you're home. What you pump is not an indication of if you're making enough. Some women get little to nothing when they nurse, but are producing more than enough milk.
Yes, some women have success with herbs. Personally, I prefer a tincture over dried herbs. My favorite is the Nursing Mothers Blend from kerrysherbals.com. Keep hydrated and take in enough calories as well. Coconut water and pineapple juice aren't going to help with production, other than keeping you hydrated and providing calories.
And if it comes down to it, there's nothing wrong with supplementing with formula during your work hours.