In this image they have the Diesel Jeans styled with the blouse on the outside, but I think that the great part of a higher waist jean is you have the option to tuck the blouse in or leave it out to make it more casual. With low-waist jeans the only option is to leave the top out or else you get this muffin top affect.
Levis actually offers two styles---at the waist (not ad dramatic) and hi rise...you can opt for either and get the same effect-a covered bum:) And as you can see in the styling above, the top is tucked in and you can see all of the details of the accessory, the belt-which is a strong accessory these past few years, so why hide it by a blouse because your jeans go too low??
Wearing higher waist jeans not only keeps the crack from showing, but also gives you a longer leaner look. The only time I would wear them with flats is if the style is a high waist cigarette jean. Otherwise, just reaching for the sky in this style wearing high heels or wedges.