Resize your or someone else's boobs!
Open up a new image of you or someone you want to apply this effect on.
Not that Jennifer Love has small breasts, she already got great ones :D
Go to Filter>Liquify and choose this option and a nice brush-size;
And there you have it... Huge boobs!
For those who didn't notice the difference.. look at this:
This really can be done on every image. And note this: no-ones breasts are too small, I don't want you to get boob-issues ;)