You need to avoid at least three kinds of pronoun-antecedent problems: missing or faraway antecedents, anticipatory references, and ambiguous antecedents.
Problem 1: Missing or Faraway Antecedents
"It" and "they" seem to be especially tempting to use without an antecedent or with the wrong antecedent, so be especially vigilant around them.
Our first antecedent problem concerns antecedents that are missing or very far from their corresponding pronouns. For example, it would be incorrect to write, “Here at work they expect us to show initiative” (1). In that case, “they” does not refer to any plural noun. Those lurking bosses are implied but not actually mentioned. Therefore, the antecedent is missing. To solve this particular error, we you could name the people instead of using a pronoun. You could say, “Our bosses expect us to show initiative.”
Of course, an antecedent isn’t always in the same sentence as your pronoun. If your previous sentence is about your bosses, it might be fine for the sentence to read “Here at work they expect us to show initiative.” Still, it’s a good idea to keep your pronoun close to your antecedent, so you might want to flip the sentence around. “The bosses gave us a talking to last week. They expect us to show initiative here at work.”
Now for the first of those silly sentences we promised you. This one comes courtesy of the useful Grammar Desk Reference: “Breathe in through your nose, hold it for a few seconds, then breathe out through your mouth” (2). This misleading sentence illustrates how easy it is for readers to accidentally think that the antecedent is the noun closest to the pronoun. The pronoun “it” seems to refer to “nose,” the singular noun closest to the word “it”; however, the writer did not mean for you to hold your nose. What’s missing here is a clear antecedent: “your breath.”
For some reason the pronouns "it" and "they" seem to be especially tempting to use without an antecedent or with the wrong antecedent as you saw in the last two examples, so be especially vigilant around them (3). “It” and “they” also seem to be likely to appear far from their antecedents. Making your reader search through an entire paragraph to find the antecedent for a lagging "it" or "they" won't endear you to your audience (4). So when you use an “it” or a “they,” make sure a specific and definite antecedent is nearby.
Problem 2: Anticipatory Reference
Our second antecedent problem is what’s called “anticipatory reference,” which Bryan Garner calls “the vice of referring to something that is yet to be mentioned (5)," meaning that the writer puts the pronoun before the antecedent—a no no.
Whoever came up with the phrases “Don’t put the cart before the horse” and “Don’t count your chickens before they hatch” could have been talking about pronouns that appear before their antecedents. For example, if you say, “If it’s available, be sure to order the champagne,” your readers will wonder what “it” refers to. Only when the readers get to the end of the sentence do they learn that “it” means “champagne.”
To make it easy for your readers, make sure the antecedent comes first. In many cases, you can solve the problem by switching around the noun and pronoun: “If champagne’s available, be sure to order it.”