Rihanna has so many crazy styles that you’re bound to find something at your local Forever 21. I went with some of my favorite Rihanna staples: over-the-top gladiator boots, layered chains and bustiers.

Metallic Brow Flat Top Sunglasses ($6.80)
Faceted Bead Bib Necklace ($5.80)
Strapless Peplum Top ($19.80)
Mini Knit Skirt ($6.90)
Tall Gladiator Heels ($39.80)

Diane von Furstenberg’s hippie glam spring collection for ‘09 looked gorgeous in Bryant Park. But when Whitney Port wore one of the runway headbands in real life, it looked absolutely ridiculous. But paired with a fringe vest and some tie-dye, the dangling flowers make a fab Halloween costume.

Dangle Satin Chiffon Headband ($7.80)
Fringe Leather Vest ($39.80)
Tie Dye Chiffon Dress ($24.80)
Drew Platform Pumps ($22.80)

Of course, the easiest way to do Lady Gaga is to throw on fish nets and undies. But not all of us are comfortable prancing around in our panties. This look still gets the point across while keeping your bum warm.

Party Bow Headband ($3.80)
Collapsible Two Tone Sunglasses ($6.80)
Satin Corselette ($9.80
Zipper Front Satin Skirt ($19.80)
Patent Platform Pumps ($24.80)

My friend was pretty upset when I told him I’ve never seen nor read any of the Harry Potters. But I know a good Hermione dress when I see one. This is such a simple costume. The only thing Forever 21 is missing is knee socks, which I find pretty shocking. But you might already even have a pair in your sock drawer.

Belted Plaid Trim Dress ($34.00)
Quilted Cap Toe Flats ($16.80 $13.44)
Polished Metal Bobby Pins ($2.80)

I was a little disappointed with the movie Where the Wild Things Are but I still left wanting to cuddle with those big wild things. As much as Jen and I mocked this vest in the store, it’s pretty perfect for a fuzzy beast costume.

Petals Wire Headband ($8.80)
Colorblocked Fur Vest ($39.00)
Velvet Leggings ($11.80)
Sweet Faux Fur Slippers ($7.80)

If you search around Forever 21, finding a costume is a cinch. And the best part is, you can wear the pieces after Halloween is over. The first outfit I found is of my fave TV character, Blair Waldorf on Gossip Girl. Now she’s being lame at NYU, so I’d rather dress like Queen B at her prime when she ruled Constance.

Satin Bow Headband ($6.80)
Sheer Ruffle Front Top ($29.00)
Swing Pea Coat ($45.80)
French Terry Tennis Skirt ($14.90)
Opaque Tights ($5.80)
Crackled Metallic Flats ($18.80)