There are many factors that influence growth of breasts. These include nutrition and genetics, both because of hormone stimulation. Breast growth is one of the important things that happens during puberty. The pubertal hormones produced by the pituitary gland (located in the brain and responsible for producing a variety of hormones), play a critical role. One of the earliest signs that puberty has begun is enlargement of the breasts as a result of increased production of ovarian estrogen stimulated by these pituitary hormones. Boys also often experience breast enlargement during the early stages of their pubertal growth spurt, but their breasts usually shrink in size after one or two years. As long as estrogen continues to be secreted in females, breasts will grow and/or maintain their size. Breasts may also enlarge slightly in women taking birth control pills or, after menopause, estrogen-replacement pills. Naturally, breasts enlarge during pregnancy as a result of marked increase in estrogen secretion. Girls with poor diets and weight loss may notice that their breasts get smaller. If these girls improved their nutrition, their breasts would enlarge to their previous size.

Aside from surgery and altering your hormone balance (e.g. birth control pills), neither of which I recommend, I don't know of any way to enlarge breasts. However, there are exercises that in the past were recommended for breast enlargement. Basically, you lift your arms and thrust your chest in and out repeatedly... I've never done it, so if someone has an easier/more accurate description, jump right in! These exercises will NOT actually change the size of your breasts. Breasts are largely fatty tissue, and there are no exercises to grow fat. What they will do, however, is build up the chest muscles directly below your breasts. This can push the breasts outward. Even though they have not changed in size, the fact that they will protrude more gives them the appearance of being a bit larger. It won't be a huge change... if you're looking for a more appearance-altering technique, I recommend a well-padded bra.

It's not really fair to say surgery is "not recommended". I know dozens of women who are superbly satisfied and happy with their breast augmentation. Yes, it's surgery, and surgery should be avoided when possible. But if your breast size is limiting your life experience, surgery may be a good solution.

Probably it can be done. See this link: http://www.mybodypart.com/non-surgical-breast-enlargement.html

I attended a "Bra Party" organised by a local company here. The presenter put water into a plastic bag and placed it into a bowl that was too small for the volume of water in the bag and the excess fell over the side of the bowl. She said that most people wear bras this way as they think that this is fat and do not push it into the bra. Over time, the flesh sags and the flabbiness will show under armpits and becomes obvious when sleeveless or tight t-shirts are worn. This link provides two video clips on bras "how tos" http://pinkrockcandy.blogspot.com/2007/06/be-bra-expert.html I lost the link to another that teaches you how to push up your breasts while wearing your bra to enlarge size. A good message to the young that you do not require surgery to enlarge breasts size. Just wear the right cup size and do the right push up and you will look bigger and slimmer.