V-neck is formed by two diagonal lines from the shoulders that meet on the chest creating a V shape. The depth of the V can vary, ranging from demure styles to plunging. The surplice version of this neckline is an alternative. The V may also be truncated by a small bottom edge, forming a trapezoid. Different types of V-neck collar may achieve different effects. For instance, light V-neck looks mature and elegant, while deep V-neck expresses sexiness.
One-shoulder neckline is asymmetrical linear necklines that cut across the torso diagonally, usually from one shoulder to under the other arm. This kind of neckline is quite fashionable and graceful. You may also add some embellishments like beads, flower detail, and so on to decorate the one shoulder.
http://www.whiteazalea.com/mother-of-the-bride/3193-sequin-sweetheart-sheath-short-mother-of-the-bride-dress-with-matching-jacket.htmlSweetheart has a curved bottom edge that is concave down and usually doubly scalloped to resemble the top half of a heart. The side edges often converge on the neck, similar to halter necklines. Sweetheart necklines accentuate the bosom. Deep sweetheart may look seductive, while light one conveys elegance and sweetness. Such a neckline is usually combined with strapless or cap sleeves.
Off-the-shoulder neckline is similar to boat neckline but are significantly lower, below the shoulders and collar bone. Usually it passes over the arms but, in the strapless neckline style, may pass under the arms. These necklines accentuate the shoulders and neck of the wearer. This neckline possesses natural grace, showing off the attractive shoulders.