Check out the hot looks highlighted in Chrissy Makkas article: http://www.thefashionspot.com/style-trends/news/174539-forum-street-style-killer-combos-in-red-black-and-white
While this features clothing looks, accessories, like your jewelry, can follow the same simple fashion rules - find something you like, feel good in, and go for it.
For example the pendant necklace below is has the feel of the a classic Spanish piece, but modernized and given an edgy twist by varying the size and shape of the gemstones used in the necklace and combining that with a classically simple pendant.
Marge, of PersonalDesignz has another example of a classic all black necklace on her site at: http://www.etsy.com/listing/65129869/black-beaded-necklace-bracelet-and?
For an all black and white look, try White Buffalo Stone and Black Onyx for a timeless, casual look. This one is a "go anywhere" style:
Whatever you decide to wear, be sure it matches you - your style, your mood, your life - stay trendy, but only go to the extremes of fashion if they suit you.