Jewellery is a big thing when it comes what can make or break an outfit.
I personally also consider it as an extension to a persons personality, it can represent a memory and a way of the person to project a image of themselves to on-lookers.
Even though this is a big area to touch upon i will only look into the two most common categories of jewellery- Gold tones and Silver tones.
Typically Silver toned jewellery tends to suit cooler skin tones and Gold tones suit warm complexions.
That being said I tend not to follow this concept.
I have always been attracted to silver metals and found gold hard to pull off even with my skin tone which is Asian.
Odd i know.......
But like i said before a persons taste can not be just limited to their skin tone, I believe you need to look at all angles of their lifestyle to conclude what tone jewellery would suit them.
Take me for example I work in a corporate office, in a rainy cloudy country, tend to travel quite a lot and tend to wear cool toned clothes think blues, whites, greys and nudes. Therefore wearing gold tones jewellery on a daily basis proves quite impracticable.
What metal are you drawn more towards?