Steps

1. You don't have to be a snob to be a prep. Preps are usually classified as "Wannabes", but that's a misconception.
2. What to buy: Fake Pearls and Diamonds are all the rage on a budget. Get pretty, simple but classy jewelery. Polo shirts, Jacquards, Solid color shirts, V-Necks, skirts that aren't too short, denim shorts, jeans-preferably the ones that aren't dark-wash, dressy tops, etc. Layering is a big thing, too. For shoes, flats, flip-flops are a maybe, heels, boots, wedges, espadrilles, and cute tennis shoes.
3. On make-up, let me warn when you first put it on it's hard to stop. For eye shadows, try natural colors. What looks good on everyone is make it one shade lighter than your skin or one shade darker than your skin. Use mascara, but curl your eyelashes first to open up your eyes. For redheads, brown mascara looks more natural than black. If black mascara is too obvious, try clear or brown. It really opens up your eyes and highlights your lashes! Use blush, but not too much - you only really want to add a healthy glow to your face. Dab some foundation on spots for perfect coverage. Remember, less is more when it comes to make up.
4. Hair- wash when necessary, don't overwash. Try and get a mane of thick, glossy hair...it's not impossible. Find hair care products that work for you, it's a case of trial and error. Don't overload your hair with styling products, just eliminate frizz and add shine.
5. Skin Care. Preps look after themselves, so keeping your skin glowing and radiant is important. Wash your face in the morning and before you go to bed. If your skin feels tight, apply moisturiser.
6. Nails- For school, keep it subtle. A coat of transparent nail polish wil add shine and keep nails from breaking. Or try light pink or beige.
7. Have fun with it! Being a prep is about attitude too. Be nice, friendly.
8. In the words of Paris Hilton, Act like there is an invisible tiara on your head at all times"


[edit] Tips

* Don't do this just to fit in unless you really want to.
* Just be you.
* Don't forget to check the sale racks at real preppy stores. Lacoste, Ralph Lauren, J.Crew, Lilly P., Vineyard Vines and more have amazing sales. So check them out.


[edit] Things You'll Need

* Basic black flats. They go with almost everything.
* Get other cute flats.
* If you can't afford a designer bag, get a cute but basic one. Or save up for a classic designer bag that will last forever and be in style the same length of time.
* Polos are key for being preppy.
* Oxford shirts are also very preppy.
* Ask for a string of pearls for Christmas or your birthday. Not very long. A tad bit longer than choker length.
* Ribbon belts.
* Argyle sweaters.
* THE OFFICIAL PREPPY HANDBOOK! It's out of print so look for it on Ebay or Amazon.

Source: http://www.wikihow.com/Look-Preppy-on-a-Budget