Pumping amounts?

Sue

2 months after the birth of my daughter, I'm finally preparing (and dreading) heading back to work. I've pumped throughout my time home but recently the amount I get from pumping has been lower (only 2-4oz, typically at least 5). Naturally, now I'm stressing that my baby isn't being enough when she nurses and that I won't be able to pump enough for my time away from her...

Anyone have any great tricks to help produce more breast milk? (i have recently began drinking Mothers Milk tea.)