Spring's erratic weather calls for smart layering, and this oversized Isabel Marant jacket might just be the ultimate wear-over-everything solution. Bonus attributes: it's a fresh update on the long-loved army jacket and it exudes ahead-of-the-curve hipness. Plus, its boxy silhouette is completely in sync with Fall 2012's coolest . Wear it with...

1. Etoile Isabel Marant oversized jacket,

2. Diane Von Furstenberg neon-trimmed cardigan,

3. Etoile Isabel Marant lace sweatshirt,

4. Citizens of Humanity cropped skinny jeans,

5. Repetto leopard-print leather slippers,

6. 3.1 Phillip Lim black leather satchel,