Drink a ton of water--at least 64oz or half your weight in ounces if you weigh more than 120.
Eat oatmeal everyday.
Take some fenugreek or try Mother's Milk Tea (with honey)--you can find in a lot of grocery stores now.
I've also heard lecithin be recommended in LLL meetings to help milk flow more readily.
Avoid caffeine and antihistamines/allergy medications.
Drink a beer.
Nurse on demand.
Don't use a pacifier.
When you are together SUPPLEMENT with formula...don't REPLACE feedings with formula. Always offer the breast first and then offer a few ounces of formula.
Are you using a good, electric double pump? I know some moms get amazing results using a manual pump or expression, but I believe that they are the exception rather than the rule.
If you are back at work, pump even if you aren't getting anything. I know it can be discouraging, but the stimulation can help your supply. Not every woman is able to get milk with a pump...you shouldn't assume you don't have adequate supply based on what you get with a pump. It is estimated that in the BEST CASE scenario, more women will only be able to pump 60% of what a baby could get.