Exercise
Exercise can build muscle around your breasts especially bellow your breasts, which can result in a little bit lifting to your breast, maybe that will not get you bigger size, but better shape and your breasts will look bigger. But you need to be supper careful with your exercise; some women build muscle in the upper chest, this muscle will push the fat of your breasts downward and flatten your chest.
Diets
Breasts are largely fatty tissue and you want to grow fat in this area not burn it, breasts are highly affected with diets, so if you are having any kind of diet you need to consult you dietant what to do to maintain breast size. In this case most women are using pills and creams to maintain if not to grow their breast size.
Clothing.
The best bra is the bra that gives you the perfect shape, even if it's not your real breasts shape. The bra must gently lift your breast up without squeezing the lower area and the nipples, the weight of the breasts (if the breasts are loose up) will stretch your skin. Flimsy cotton and lace may not be strong enough to pull your breasts up.
Your bra must gently push your breasts up and toward each other, so the erotic curve appears.
Underwire bras give a good lift to your busts because they provide good support underneath. Just make sure the wire surrounds the breast tissue and is a perfect fit to your breasts otherwise you'd be uncomfortable to wear them. And now you can find some kind of hard fabric to replace the wire. You know that breasts are highly sensitive, and when erotically aroused they harden and change shape (mostly to the desired shape). So try to wear (at least in private at home) a lifting bra, while leaving your nipples loose, with large loose t-shirt (preferred to be silk). The touch of the silk on the nipples can harden them, and if they stay hard for some times, the blood circulation and the hormones make your breasts harder. This technique is painful some times.
Massages
Breast massage can be tricky because breast tissues are quite delicate. However, if done properly and with exerting only moderate pressure, massaging the breasts are perfectly safe. Not only does massaging the breasts make them firmer, it also makes them healthier and aids in maintaining the balance of hormones in a woman's body. To avoid friction and discomfort, the lubrication of massage oil on the skin is also necessary.
The general massage is in circles from below the breasts trying to gently push them up and into the middle chest area. So your hands will go beneath your breasts in and out with a little left and squeeze beneath the shoulders. The second technique is your hand will go from beneath your breast up and down pushing your breasts up, and after your hands pass the nipples try to pull your breasts up by gently squeezing the upper skin. You will find more information about breasts massages and breasts exercise with great woman's health products