Using a breast-pump to express regularly helped me, while I also found drinking plenty of water (especially a glass or two while feeding) helps to increase the supply.
In saying that, unfortunately some women simply have a low supply.
You can always ask a maternal health nurse for suggestions if you find that nothing will work.
Good luck :)
There is a tea called "mother's milk" that you can buy and it helps to increase milk supply...also you can pump after every feeding. make sure that you are feeding your infant on demand and letting him/her go as long as he/she wants to (not stopping the feeding, just letting baby pull off when done and then offering the other breast). If you do give a bottle or skip a feeding for any reason, you should always pump in place of that. Also, drinking plenty of water and eating healthy are always good practices.
Here is a helpful list of herbs and supplements that can increase your milk supply (take out the space) http:// en.wikipedia.org/wiki/Galactagogue
A galactagogue is a substance that promotes lactation in humans and other animals. It may be synthetic, plant-derived, or endogenous.
The most commonly cited galactagogues are herbal. The most popular of these are:
red raspberry leaf
marshmallow (althaea) root
forget herbs and supplimenst. Its all to do with hormones.
Your brain registers when you feed your baby, it then releases hormones to make more milk. The more you feed your baby the more milk you produce. Your breasts dont store milk its gets mad on demand so women that think they will skip a feed and store it up for next time - sorry that doesnt work your body will just stop producing milk.
The best time to feed is at night - in fact you must feed at night if you believe your having issues as thisisi when your hormones are at their milk making best. If your little one is sleepimg thro, then try expressing, although i wouldnt reccomend feding it as mots babies wont switch between bottle and breast.
Another tip is not to detach baby, even if you think its asleep, its actulay is just resting. not draining both breasts of milk is also a classic "im not producing enough milk" reason.
Good luck and keep going, if you find it hard - get help.