Avoid Sexist Language
The "he or she" problem
Most composition theorists now agree that it's unacceptable to use masculine nouns and pronouns to refer to the whole human race. A sentence like "Man's hunger for knowledge has always distinguished him from other animals" may technically include women, but do you really "see" a woman in your mind as you're reading it? Since women are just as hungry for knowledge as men, it's important to include them.
Of course, using terms that include both genders can become awkward. One of the biggest problems arises when you are trying to discuss a group of people using a singular representative. Take the following lines, for example:
When writing for a magazine, the writer should find out as much about his or her readers as he or she can. He or she should research the magazine's subscriber base, to learn what writing style he or she will have to use.
This is obviously clumsy. However, such problems don't mean that you should revert to calling the writer "he." Using "they" to refer to a singular noun is becoming more common (as in "the writer should find out about their readers") but is still technically incorrect.