I once wore a skirt over dress pants to a club and a male friend of mine chided me: "What, you couldn't decide between them so you wore both?" Bingo.
I don't know if it's the gypsy in me that draws interest to wearing multiple pieces at a time, but I do love pairing the usual with something that makes it unusual; whether its high socks peeking through the tops of knee boots, dresses over jeans or a bunch of accessories layered accordingly. In the fall I love the look of long sleeves peeking under short sleeves or a jean jacket paired with a cocktail dress. It's really all about the expected meeting the unexpected.
I had a friend/roommate that taught me a lot about personal style. I used to marvel at her talents of throwing things together and making them look good. I once saw her wear turquoise and blue and thought to myself that I would never think of wearing those two colours together.
Style to me is not wearing the most revealing clothes. I've often been complimented on my personal style but I'm usually covered up in multiple layers so if you love to be scantily clad and revealing, the layered look is not for you.
I admit, sometimes I look back on photos and think that I looked like a Christmas tree wearing multiple shades of colours and accessories, sometimes all at once. I've evolved a bit since 1999. You want to be careful to be subtle with the layers or you could end up looking like a grunge bohemian bag lady.
Here are some images to inspire you!