Most of us look better with clothes onwe can accentuate our good parts and hide the rest.
Alas, your résumé lays you bare for all to see. That's why employers almost always require job applicants to submit one. It enables employers to see all your warts: the gaps in your employment, the downward trend in your employment history, etc.
Sure, if your résumé is likely to make your target employers swoon, send it on. If not, you'd be wise to play the "Hide the Résumé Game," just as a person might want to defer revealing a Buddha-bellied body to a new sweetie until after building a relationship.
Even if a job ad requires you to submit one, don't, unless yours is likely to win first prize in the beauty contest. Let your application stand and fall based on a well-written cover letter. An employer is more likely to keep you in the running with a great cover letter and no résumé than with a great letter negated by a mediocre résumé.
But what happens if you don't submit it and the employer later phones you, saying, "We'd like to see your résumé"? The best answer is to keep deferring: "I'm working on it. Would you mind if I brought it to an interview, if you decide to interview me?" At the interview, don't offer your résumé unless it's asked for. A surprising number of times, they won't ask or will do so only at the end of the interview, by which time you've had a chance to reinforce the positive impression you made with your cover letter.
What is an effective cover letter? One with bullet-presented accomplishments and attributes, each of which would impress your target employer. Example:
Dear Mr. Johnson:
I was excited to see your job opening for a marketing manager on monster.com. I believe I have all the qualifications.
(List the job requirements as stated in the ad.)
How I meet those requirements
Of course, there's more to me than can be shown in a letter. For example, my coworkers say I'm a pleasure to work with. So, I'm hoping you'll interview me so you can get a better sense of who I am.
Hoping to hear from you,
Along with the cover letter, you might also include a work sample. For example, a teacher might provide a videotape of a lesson, a programmer might send a piece of code, a scientist might include an article on research findings.
When day is done, the average applicant who plays the "Hide the Résumé Game" will land a good job faster than one who, like a good little child, submits the résumé as "required."