Seriously, I know tons about this subject
The biological way that is proven to work (cutting edge though out for a while to have been tried and tested) and the ladies would love the double whammy effect of it (as would the guys lol) is stem cell breast augmentation.
Essentially what they do is liposuction your own bodyfat from areas youd like slimmed

and then they take out the stemcells from the bodyfat ), process the bodyfat and inject it with combination of your stemcells(which have now been enzyme activated) into your existing fatty breast tissue with a supporting splint to keep everything in place.
Results? You literally grow your own breasts whilst slimming down any problem spots
The breasts feel fantastic(real thing) and as they are fatty tissue like natural breasts, they do not interfere with mammograms or show up on stupid body scanners etc.
Also they are not a foreign body so no reaction issues or fears of leaks etc. Also unlike attempts in the past where the injected fat would be reabsorbed etc and hence breasts would sink in/deflate, this method propagates the existing breast tissue and the injected fat forming fully developed blood lines etc ie once its formed and fully developed it aint going anywhere as it becomes part of the breast.
This is commercially available and has been on offer for a while now though very very few people have heard of it and very few plastic/cosmetic surgeons even know how to do it. It does cost a bit more depending on surgeon and country etc BUT the results last with no need for revisions, removals etc. ~$25,000USD is about cheapest I have seen it for.
Can increase upto 2 cup sizes eg b-c into a perfect DD mmmmm
Another similar concept based procedure that is still in development is called neopec. This is more ideal for cancer sufferers etc and takes a lot longer ~8months or so and is based on improvements of the above method.
Essentially they mold a biodegrabable synethtic chamber to the size, shape and specifications needed for the patient, then redirect some blood vessels into it from the underarm, where it is connected with 5mls or more of the patient's liposuctioned processed fat and stem cells. Over the coming months that tiny spec of implanted fat grows to fill up the chamber and as it does so that chamber slowly biodegrades till eventually a fully formed breast without any chambers is left behind.