From Capital Chic Patterns:
Martini is a cocktail dress with a twist. In today's crop-top shape with an above-the-waist skirt, the silhouette helps create the illusion of a narrow waistline. It comes either as separates, so you can show as much or as little skin as you like, or as a lined dress that looks like separates but without the risk of showing any midriff. The top has a slightly sporty look with the armholes cut with a hint of racer.
View A is a fully-lined cocktail dress. Features include an invisible zip and zip guard, a lined vent and optional boning at the waist.
View B is a high-waisted skirt and cropped blouse that can be made in matching or contrasting fabrics. Features include a separating zip in the top and an invisible zip in the skirt, a lined vent in the skirt, and boning at the waist to create a smooth line.
The instructions for this pattern include full descriptions of advanced techniques such as boning, french seams and inserting the zip guard, making it ideal for sewing intermediates looking for a challenge.