increasing lactation

Does anyone have some tips on how I can make more milk? (I'm in the first month of breastfeeding &  pump occasionally). some days I just don't make that much, but other days I'm SOO engorged and feel like my boobs are full of rocks. my lo eats frequently and latches good. I also take postnatal vitamins with breastfeeding support. Should I try a lactation tea? Or cookies? Anythingggggggg