Connect to Your Argument
Your title needs to reflect the argument presented in the paper. Part of a title's purpose is to tell the reader what the paper is about. For instance, "Legalizing Marijuana: Colorado's Biggest Mistake" tells the reader the paper covers marijuana's legalization and expresses the writer's opinion that Colorado erred by approving such a measure. You might begin by writing a single phrase that summarizes your argument -- say, "making marijuana legal is a bad idea" -- and then reworking it to come up with a succinct, engaging statement.
Create an Interesting Idea
An effective title also grabs the reader's attention, making her want to read the essay. Play off a thought-provoking phrase, such as "The killer's innocence," which combines two different -- and seemingly opposing -- ideas. Especially when combined with words that clearly reflect your argument, such phrases make strong titles. "Happily Never After: Stuart Goth's Innocence" plays on the well-known "happily ever after" phrase and tells the reader the paper will argue about the innocence of this man. Without knowing anything about the case, the reader can glean that this paper tells the story of a man the writer believes was wrongly convicted for killing his wife.
Convey Consistent Tone
The title should match the attitude and tone the argument puts forth. If you choose a lighthearted topic, such as why a movie should win the award for the worst ever, your title should similarly convey a humorous tone, such as, "'Movie X': A Shining Example of Everything Wrong in Hollywood." If you argue a serious topic, choose a similarly sober title. For instance, an argument about the dangers of the Internet might use the title, "The New Child Predator," a serious and frightening title that matches the content.
The language for your title affects how well it works. Use a phrase rather than a complete sentence, eliminating unnecessary words, including verbs when possible. Try writing out your title as a statement and then pare it down, replacing weaker words with more enticing language where possible. For instance, the idea that companies should not market to children might become the title "Down With Ronald McDonald," an interesting title that tells the reader the attitude and general point of the argument. Avoid superfluous language such as "an argument over" or "research into."