I second the cabbage leaves and the hot showers. I also used motrin and drank peppermint tea and ate lots of the herb sage as those are supposed to reduce mike production.
This is from the Kellymom website:
Herbs that may decrease milk supply
Using large amounts of the following herbs and other natural remedies should be avoided while nursing because they have been known to decrease milk supply. The amounts of these herbs normally used in cooking are unlikely to be of concern; it's mainly the larger amounts that might be used therapeutically that could pose a problem. However, some moms have noticed a decrease in supply after eating things like dressing with lots of sage, sage tea (often recommended when moms are weaning), lots of strong peppermint candies or menthol cough drops, or other foods/teas with large amounts of the particular herb. These herbs are sometimes used by nursing mothers to treat oversupply, or when weaning.
Black Walnut
Chickweed
Herb Robert (Geranium robertianum)
Lemon Balm
Oregano
Parsley (Petroselinum crispum)
Peppermint (Mentha piperita)/Menthol
Periwinkle Herb (Vinca minor)
Sage (Salvia officinalis)
Sorrel (Rumex acetosa)
Spearmint
Thyme
Yarrow
Good luck!
H.