I have to say, I love her style too! I've spent a good couple hours putting together clothes to figure out exactly what her style is.
As you know, Aria's character is the artist chameleon. So her style mainly revolves around being herself. Her style is what some call, Goth Indie. So, I suggest getting some calf high/knee high boots, preferably black, since this goes with everything and shows the goth part of the outfit. Aria is really into the mesh/texture look. You see her pairing a short dress, a long jacket and some cute knee high boots. Go for that look. I suggest shopping at Forever 21, or Hot Topic. In Hot Topic, go for the leggings. Lace leggings. When it comes to tops and dresses, go for something satin, or again, something with texture. For example, http://www.bergdorfgoodman.com/store/catalog/prod.jhtml?itemId=prod56720016&ecid=BGCIFroogleFeed&ci_src=14110944&ci_sku=T2PT0
This combo outfit ties in texture and classiness.
For hair, I suggest getting a curling wand. Conair's Infinity Curling Wand works wonderfully. To get her look, you should probably dye your hair in a dark black/brown. Because have you seen the hair on that girl?! Gorgeous, it also ties everything together. Slightly brush out the curls, but don't make the curls TOO curly. You want a tousled look. If you can't buy one, get your straightener and slight twist it. It'll curl under slightly and when you go to a new piece, twist it slightly more, it'll set apart each piece.
And for the makeup, Aria goes for a dark eye, then a nude lip. And she enhances her eyebrows with a dark eyebrow pencil. For the eye, start on the lid with a brown, Try Cork from MAC. After you get that on the lid, smooth it out so you have no hard lines on the eyeshadow. After you get that on it, get your black eyeliner and line as close as you can get to your lashes. After that, smudge out your eyeliner and then take your black eyeshadow and go over it, bringing it out to the brown a little bit. Get a shadow a little lighter then your skin color, and put it on the inner dip by your tear duct.
On the lips, take a angel pink, or a light gloss. For the gloss, I suggest Victoria's Secret lip gloss, Blush. For a lip stick, use MAC's Angel shade.
All the links to the eyeshadow and lip sticks are down here..
Lip Sticks, go under angel.
Eyeshadow, Cork and Black Tied.
Me, Myself, and MAC. :DD