There are two kinds of natural breast implants - natural "looking" breast implants, and naturally large breasts without implants. And you don't have to be born with the latter. There are a lot of very effective products on the market today that will enhance your bust line naturally. (Your friends will think you spent the money for real implants.)
The trouble with most breast implants is that you can spot them a mile away. You've seen the look - the "shelf" of breasts, the boulders on the beach (that don't float naturally to the side when she lies on her back), and the bazoongas that look like they could take over a small country not to mention their owner's neck, blouse and date. But you can have natural "looking" breast implants if you follow these three tenements:
Don't go too large for your frame. Your new shape should not branch out further than your hips. If you have a very small waist, double D cup breasts are going to look a little odd, so consult with your doctor to make sure that your new look doesn't expand the boundaries your body.
Massage your new breasts. As you've no doubt seen, breast implants can stiffen up if they're not taken care of immediately following surgery. By gently massaging your breasts every day for the first six months after surgery, you decrease the chance of stiffening and increase the chance that your new breasts will look as beautiful as you always imagined.
Saline is better than silicone, tear-drop is better than round. Although there are still risks associated with saline implants (they make it harder to detect cancer, they are still not considered "permanent" devices and women with implants will have to have multiple surgeries over their lifetimes for various reasons, including implant rupture), the risks are a lot less than with silicone breast implants. And, because saline is liquid (salt water) the implants move more naturally than the stiff silicone gel implants.
The alternatives to surgery are a lot less expensive and have no risks. And because they are natural, you can be sure that the increased breast size can be supported by your body (and won't take over any small countries). The best are herbal breast enlargement pills, which balance your body's hormones and enhance your breast size by one to three cup sizes.
There are also breast enlargement creams, which help to firm and tone your breasts. And breast enlargement pumps, such as the FDA approved Brava, which helps to increase your breast size over time by expanding the breast tissue.