At 12 I don't think you should be worried about making your breast look bigger, but there are push up and padded bras.
How can i make my breasts look bigger? I am 12 and only a 32B. How can i make my boobs look bigger without surgery?
May be you should use a foam so that your breast look bigger because at your age you can't be in a surgery and secondly your are just minor why are you thinking that your breast bigger more because your just 12 and soon that would be possible / use foam
Do exercises before you sleep
Push up bras.
Lol just wait for time to pass by xD Most women don't finish fully growing their breasts until their early 20's. Since you are only 12, you still have a lot of growing to do.