Well, joking apart, a bit of exaggeration can look more real, but it depends a lot on the pose and the viewing angle. And a lot of the "references" you might find on the net are a little unreliable. Silicone implants and such are routine. Maybe some models have better morphs, but the ones I have seen are biased towards naked breasts. Clothes tend to bring the breasts together, making the cleavage a little more prominent. And there are gravity effects. But all these things have been something artists have had to deal with for centuries. All those nude models and life art classes are more than just lechery. We don't have to learn the same mechanics of putting lines on paper, but we're in the same business. And it's OK to feel a little embarrassed. It hits me sometimes, but when you're actually making the art, working on the image, it sort of drifts to one side. The process, whatever the medium, puts a distance between you and the reality. Usually.