The majority of my denim jeans have been customized with a pair of scissors to give them a bit of a crop (and that lovely raw fringed edge). I like to show a little ankle, because it looks more flattering and spruces up most looks.
The boyfriend style cropped denim, one of the season's denim trends, is a different story though. This style is fun, especially come summer, but more tricky to wear as it doesn't do your legs favour - optically speaking that is. Well, at least this is the case for the majority of us ladies (carry on if you're one of those lucky bastards with mile long legs). As with all fits & styles it is foremost a matter of personal preference, but personally speaking I know that cropped wide-legged jeans are harder for me to pull off. My legs aren't that short, but I have a rather long torso and usually go for a high waist to balance things out.
But, being a stubborn person who doesn't like to live by the rules that much, I wear those "no-go jeans" anyway. The key is to style it in a way that works for you (and your body type). Sadly that means no comfy kicks, but instead a pair of heels that elongate my legs optically. Adding long layers of silky black fabrics on top make the outfit more elegant without losing the casual-cool of the denim. And there you go, it's all a matter of styling rather than living by the rules...