The décolletage. It (literally) lives in the shadow of the face in terms of importance. While we're well versed in treating our faces to all sorts of serums, algae-infused potions, caviar-infused scrubs and er, bee venom, the neck, collarbones and chest area is all too often given zero attention. Still, it's understandable really - when it’s 11.39pm on a Thursday and bed time is calling, and you’ve probably had one Dark & Stormy too many - it's hardly worth giving a second thought.

And yet, buoyed by the trend for a revealing neckline, we're becoming rather partial to revealing the décolletage, as is the current roll call of red carpet starlets. It's one of the most elegant parts of the female anatomy; all contours, sculpted curves and radiant skin. However, there are stumbling blocks which are well worth avoiding. Reveal too much and the look quickly becomes gauche, too little and the effect is one of anxious timidity. 

So handily, we've compiled the 12 inarguable rules of the décolletage; explained, decoded and in the gallery below.