There are various ways of boosting supply from using herbs (also known as galactagogues), food, pumping, etc.  Just remember that your mileage may vary.  Things that work for somebody may not work for you.  Sometimes, the most 'unconventional'  or unusual ways can be very effective.

Sometimes, dwindling milk supply is actually 'psychological'' - i.e. you think your supply is going down, when actually your breasts are still producing enough for your baby.  Before you press the panic button, first determine by output whether your baby is sufficiently fed.  If your baby has enough wet and clear diapers (i.e. urine is not yellowish and concentrated), and your baby appears satisfied after feeding, is happy and growing well, then you should not worry too much.

However, if your supply is really dwindling, you can try the following and see what works for you.  Remember, it often takes a few days before you actually see the effect, so be patient.

1. Nurse Frequently

The Number 1 method of increasing supply is to nurse frequently.  Hence, if you find your supply dwindling, increase the frequency of direct nursing.

Working moms should increase the frequency of pumping at work and also increase the frequency of nursing when at home.

2. Pump after feed

Trying pumping for 5-10 minutes after nursing your baby.  The pumping will increase stimulation placed on your breasts and help to increase supply.  The aim is not to get any milk out, really, and you probably won't get much out because your baby should have emptied your breasts already.

3. Try Galactagogues/Herbs

Herbs like fenugreek, anise, blessed thistle, fennel, hops, milk thistle, nettles are all examples of herbs which are thought by many to increase breastmilk supply.  None of them are actually scientifically proven though.

You can buy tablets/capsules of these herbs from health food store like GNC and Nature's Farm.  You can also easily get seeds of fenugreek, fennel, etc from local spice stores.  Try Little India.  Simply crush the seeds and seep in hot water to make tea.

Alternatively, you can also purchase Mother's Milk Tea from online stores like Moms in Mind.  Mother's Milk Tea basically contains an assortment of herbs and save you the trouble of hunting for the herbs.

Also note that herbs are not 100% safe.  They do have side effects.  As a general rule of thumb, you should be careful with the use of herbs.