My style doesn't include many midriff baring outfits (I think I said goodbye to flat abs as soon as my baby girl arrived! No complaints though!) but I love the subtle sexiness of a cut out dress that is otherwise demure. I know it is easy to pull off a cut-out dress if you are really slim, but a crop top worn with high waisted bottoms works for most women. If you do not have washboard abs, choose high wasted skirts or pants that sit just below the flattest part of your torso. If you are heavy on top, the trick is to chose patterns (like stripes or big florals) that camouflage the top heaviness and draw attention to the flat slice of the waist.
A full midi skirt works great with crop top to give the sexy, edgy look to the outfit, yet still keeps the ladylike femininity. ASOS has some great full midi skirt options. I am wearing ASOS scuba midi skirt size 6, usually I am size 4 in skirts in most American brands.