i think...for most people they are born with a aura. but not many people breds it well enough to stand out. or their aura/energy is too common and it doesnt stand out.
it's like talent. everyone is born with a talent but they need to realize it so they can bred it. or else their talent will go to waste.
i dont think there's a definite "good" aura. it has to do with your taste. someone with a strong aura can appeal to some and disgust others. nonetheless, that energy is attractive.
but i think your features will help defind your aura just as much as what you wear, how you talk etc.
my mom and i always talk about it, but in chinese. i can express this topic much better in chinese than in english. i try explaining it to my friend but she doesnt get it.
personally. i find what you read, watch, learn, listen, interact will change that energy. before i came to canada from china around 7 years ago, my aura back than is different from now because im influenced by western culture. so when i go back to china to visit, the people there can sense right away im "different" and forgien even though i look completely chinese with black eyes and hair.
but whether that makes me have an attractive aura is another case.
there's this girl from my school that has a very distinct feel to her. she doesnt have features that screamed gorgeous but something about her attracts the eyes. even when she's practically bald she's attractive. but also intimidating at the same time.
im thinking it her attractiveness has something to do with the books she read