You can create a focus with your statement necklace by minimizing distractions elsewhere in your attire. This will allow your neckline to become the desired focal point of your ensemble. You should skip the gigantic flashy rings, excessive arm accesories, and keep earrings to a minimum, if any at all. Instead, select thin bangle bracelets or simple banded rings to accent your necklace.
Of course, there are exceptions to every "rule", you should always reflect your personal taste. Wear an outfit you feel looks fashionable, and your confidence will do the rest!