I got my oversized denim-shirt from Zara like 2 years ago, and I've always loved rocking it with darker denim, so that's kind of cool. However, it can definitely get to be too much of a good thing. I don't like any of the styles posted, except for the one on Alexa Chung. I like these ones too: Mario Schwab
I also took the liberty to re-post some "golden rules" from a Guardian article from a whle back; 1 No belt, please. With a belt, the look that you were hoping projected Paris catwalk insouciance becomes unreconstructed Idaho truck driver.
2 You need contrast in colour: One piece should be a darker-hued denim. You might want this on your bottom half, darker colours being more slimming, but beware: a pale denim shirt can wash out your skintone.
3 Don't go with a very fine chambray shirt with a very heavy denim jean. That's not double denim, that's cheating, and it doesn't have the right impact.
4 Break up the heaviness of the look with something light and feminine: the strap of a fabulous Chloé or Mulberry cross-body handbag, perhaps; or a gorgeous pair of dangly earrings; or wear the shirt open one extra button to show off a tiny glimpse of a pretty camisole.
5 Roll your sleeves up and highlight bare wrists with a bracelet or a cocktail ring.
6 Finally, no cowboy boots. Keep feet semi-naked in ballet pumps or a pretty flat sandal.