Include names, dates and other pertinent information about the objects you use in your argument where relevant. Write good hard concise prose, carefully argued and without unnecessary fluff. Think, organize and outline before you write. Consider the role of portraiture in Greek art. Begin your essay by spelling out exactly what you mean by portraiture.
Different scholars define it more broadly or more narrowly.
Consider the representations of women in Greek art of various periods. You should consider objects of different uses and with different intended audiences - for instance, women on vases intended for men's use at symposia will be differently depicted from women on vases intended for women's use. Choose examples which you consider either characteristic, significant, or both, from different periods of Greek art, and discuss how they depict women and how the depiction is related to the use and audience of the object.