Is the fact that she's wearing blue jeans or diamonds make any difference to us as the audience?
No.
All of these decisions are important, of course, to add depth to your character and also as far as it relates to the plot. But the ingredients that separate a true heroine from just a mediocre one are based on what's inside of her - the emotions and dreams and hopes and fears that make her almost human and thus, a woman that readers can identify with.
So, what are the key ingredients that can make your heroine memorable?
First, a romantic heroine must CONNECT.
She can't be so ditzy that she drives the reader mad. She can't be so bossy that she turns off everyone. She must have a kernel of her personality that the reader can grab onto and say; "I understand where she's coming from." The heroine of a romance novel can start the story with a chip on her shoulder. She can have a burning desire to climb Mt. Everest or do something that no sane woman would contemplate. But there's got to be some quality or trait that will endear her to the audience, in order for them to cheer for her eventual happiness.
Second, a romantic heroine must have STRENGTH.
Wallflowers are no longer desirable as heroines. Standing around looking beautiful, and not much else, is a sure way to turn off your reader. No, your heroine must have an inner strength that will bring her through the hardships she's sure to face, and earn the admiration of the reader. This does not mean that she must be an "in your face" kind of gal. Many a shy mouse or placid girl-next-door will surprise the hero with her strength of will. There's a myriad of different ways to show strength and it depends on what kind of woman your heroine is. But know that you must add an element of strength into her character before the story ends, or your audience will turn away in disgust.
Third, a romantic heroine must DESERVE THE HERO.
A heroine embodies all our hopes and dreams of a perfect love. After all, she gets the perfect man, so she should be worthy of this ideal love. Though she might have a run in her stocking or never pay her taxes on time, she must prove to the reader that she deserves what she's getting. To do this, she must change or grow into a woman that is a match for the hero.
These three ingredients, when used wisely, will elevate your heroine into the pantheon of memorable women that populate some of the best romances. If your heroine CONNECTS to the audience, if she has the STRENGTH to win her battles, and if she DESERVES THE HERO by the end of the story, then your heroine will be one of those characters that readers will take to their hearts.
