IT’S tempting to think of a résumé as a low-maintenance aspect of your job search. Just list where you worked, what you did and where you went to school, attach that to each application and press the button.

In fact, though, you have considerable flexibility in how you structure your résumé. The decisions you make about what it says and how it looks can affect whether you get the job you really want, or get a job at all.

A résumé is a marketing document that “can serve as a magnet to draw job opportunities to you,” said Susan Ireland, author of “The Complete Idiot’s Guide to the Perfect Résumé.” That’s largely because more résumés are now on job boards and social media sites, and are included on company databases, she said.

Often, people place too much emphasis on the parts of past jobs that they hated — and get new jobs they end up hating, too, she said. “Your résumé is about your future,” she said, “it’s not about your past,” so stress experiences that are most relevant to the position you aspire to hold.

Let’s say you were in a data-entry position but want to move into project coordination. Give your true job title, she said, but you can highlight the parts of your job that involved projects.

You aren’t obliged to list every single job you have ever held. If a job is 15 or more years in the past, stop and consider how much it’s worth mentioning, or how much space to give it, said Wendy S. Enelow, a résumé writer for executives and co-author of “No-Nonsense Résumés.”

“Your résumé is not an autobiographical essay of your entire life,” she said. If the sales job you had 20 years ago does not relate to where you are headed, leave it out or summarize it very briefly, she said.

In listing your most relevant experience, quantify your achievements whenever possible, Ms. Enelow said. For example, you could write “automated internal record-keeping processes, resulting in a 27 percent reduction in annual operating costs,” she said.

People with gaps in their recent work history often balk at a résumé that lists their latest jobs first, thinking that a “functional” type, stressing skills rather than dates, will work in their favor. But in most cases, job seekers should go the reverse-chronological route.

Most hiring managers become suspicious when they see a résumé without prominent dates, Ms. Ireland said. Try to list things like your community service, your volunteer work or other activities to fill in gaps in your recent work history, she said.

Many companies use software to weed out unqualified applicants. Pay attention to key words, repeating some defining terms from the job description. For example, if you are applying to be a solar energy engineer, you could include the words “solar,” “installation” and “photovoltaic (PV),” Ms. Ireland said.

Be concise in the job-objective or summary part of the résumé, which comes after your name and contact information. If you are seeking a position similar to one you have held, simply state your professional title, Ms. Ireland said (for example, user interface architect). Otherwise, indicate the job you want next or emphasize the skills that the job involves.

Tweak your résumé when necessary. Be sensitive to wording differences among industries. For example, banks have customers, while libraries have patrons and hospitals have patients, Ms. Ireland said.

Generally, unless you are a very recent graduate, list education after work experience. The older you are, the less necessary it is to list the year you graduated, Ms. Enelow said.

Make sure your résumé is easy to read, both on the screen and on paper. Even though most résumés are sent via e-mail, many H.R. people still print out the attachments, Ms. Ireland said.

Résumés are shorter than they were even five years ago, Ms. Enelow said, perhaps as a result of social-media behavior like 140-character tweeting. Keep them “tight, lean and clean,” she said. Ms. Ireland warns against the “big cement block” effect, meaning the use of dense paragraphs. A paragraph should be no longer than three lines, she said.

Make good use of white space, point size, boldface and bullets. But if you start seeing a laundry list of bullets, group them into clusters under skills headings so they are more readable, Ms. Enelow said.

And if you are a mid- or late-career professional, don’t feel that you must keep your résumé to one page.

Many companies have older versions of Microsoft Word, so make sure that your résumé attachment is compatible with them, Ms. Ireland said. It’s also wise to have printed versions ready, to hand out at interviews.

Finally, have someone review your work. If you need a complete makeover, the services of professional résumé writers may cost from $100 up to thousands of dollars, Ms. Enelow said.

But even an extra set of eyes from a friend, family member or career center employee can be enough to set a wayward résumé on the right course.