Narrow the focus so that you don't have to discuss all things everywhere. Choose one to three cultural practices -- perhaps child labor, the death penalty and how families and communities get potable water, for example.
Research your chosen practices, considering varying circumstances. For example, considering attitudes about child labor, you might describe the typical American child's experience to that of many children in India. First ask yourself whether American children are expected to work in order to help the family survive. Consider the life of a suburban American child, but also of those on family farms and in other family owned businesses to which children often make needed contributions. Then objectively compare that to the experience of a child in India whose family may earn money through cottage labor, a practice in which a family is paid for piecework such as making rugs, and in which the pay for each piece is so low that the family will not have enough money to eat unless the parents put their children to work.
Write a rough draft in which you set out the issues, figure out how to organize the content, and evaluate it for appropriate scholarly support, completeness and to see whether you have treated the material in a fair, unbiased way.
Explore whether one culture's practices are right or wrong compared to those of another culture, or whether they are just different for practical or cultural reasons. Beheading, perhaps. Discuss what moral or legal criteria a culture uses to decide whether to use it as a criminal penalty. Compare the practice between cultures. For example, consider that France used beheading as a criminal penalty well into the 20th Century. Consider which cultures use it today, why they use it and whether France in 1981 was more or less ethically correct and more or less cruel than another country that still uses beheading as a criminal penalty. It is important to examine contexts and circumstances in this part of the essay.
Reflect on what you have learned, in the last section of the essay, about either your world view or that of a typical American as it compares to the world view of people in other cultures. Discuss how people develop a world view and whether looking at other people's cultures in an unbiased manner is a worthy practice, and also what the limitations of objective considerations might be in the light of universal truths, morality or ethics.