Q - "You and many others have mentioned the necessity for a "little black dress" but why? And how do I keep it my style? They all seem to be so "little!"
First, the Why. Everyone needs in their closet the "instant elegant outfit." Something you can put on and never have to question how nice you look. Because this outfit must be appropriate for all occasions it has to be a versatile. Versatile is easiest when it's in the form of a neutral base that can be accessorized a million different ways. Black is universally flattering - every woman in the world can wear it in some way or another and look lovely. It's the perfect backdrop to anything you'd like to do with it. And no, it doesn't have to be "little".
It's nearly impossible to find pictures of Coco wearing the dress, but I found the one above that someone took with a stuffed monkey.
Second, the Personalization. In answer to your other question, I offer the many examples below. (Click the images to enlarge.) The LBD you choose should a) speak to your social life and b) reflect your personal taste. For example, if your social life consists of lots of fancy dinner parties with your husband's company and clients AND you like a dash of retro, you might choose something like the dress on the far right below.
And once you have it - WEAR IT! Wear it often, wear it well.