If you're a thrifty spender, this Oasis Shawl will fit the bill. It's a fail-safe choice, while not very expensive. Another strong contender for your wardrobe is this Oasis Necklace. While the price of this piece is rather reasonable, it will surely attract a lot of attention.
If you can afford it, then you absolutely must check out this Oasis Headband. This product seems pricey, but it's well worth it.