SINCE A GIRL's "shining glory" truly is her hair, I think it is very important to pay extra special attention to your "Barnet" -- that's London slang for hair-do.
My hair is long, so I am writing this only for girls with long hair (or girls who plan to grow long hair). First off, cleanliness is the number one beauty secret when it comes to long hair -- or any hair, I s'pose. I usually wash my hair once a day. I dry it in a clean linen towel, then carefully and gently comb all the tangles out.
You will have to experiment with various shampoos to find the one that is right for you. You don't have to use expensive shampoos. There are very good ones in your five and dime stores. I think a shampoo with olive oil added is good for most normal hair.
Just before my hair is completely dry, I give it a good brushing with a natural bristle brush. Be sure your hair is not still wet, or you will "stretch" it and break off the ends. When my hair is gleaming (still dampish), I take about eight big round rollers and carefully roll up the ends. I curl them over about three times. You have to use more or less turns, depending on how much natural curl there is in your hair.
When my hair is dry, I remove the rollers. Then I lift the hair at the top of my head and back-comb or brush it until there is enough teased up to give me a little "crown." Next, I comb over the teasing gently until the crown looks smooth and neat. Now I comb my bangs down, over my eyebrows and, holding them lightly, flick the ends up so that I get a curved line (which is very flattering to the eyes).
Finally, I carefully comb the sides and ends, also flicking the bottoms up all the way around. The final move is to spray my hair thoroughly with a good, light hair spray. This holds it in place without getting it all gooey.
If you have trouble with this hair style, don't despair. Please keep trying and soon you will learn how to do what is exactly right for you and your hair type. Good luck!