You may be told that diamond shapes can be matched to the type of woman you are. This is mostly entertainment or hopeful advice for men attempting to choose an engagement ring for a surprise proposal. Still, there is some truth to that statement. If the woman is very traditional, she will probably prefer a round brilliant diamond in a solitaire setting, or if she is sentimental and romantic, she will likely be charmed by a pink diamond in a heart shape. If she is fashion-forward and prefers to be unique, she may like an unusual shape, a colored diamond, and a modern setting.
Rather than trying to fit yourself into a category, choose the diamond you like best, in a setting that sets it off best, or choose the already complete ring that makes you swoon. If you are choosing a ring for someone else, you may find yourself shopping (with her) for a replacement, but it is not likely that your proposal will be turned down just because the ring isn't to her taste.