I have been a career coach for 17 years, and every day, I see horrible résumés. I have helped countless people rewrite their career history over the years, and have created more than 1,000 career history summaries.

This piece of paper is so significant, but you typically only have about 5 seconds to make an impression on a recruiter. With the increasing competition in the job market, résumé tips have practically become as valuable as winning lotto numbers.

It took me years to learn how to write a successful résumé. Being able to think of your experience in a way that shows your value is not an easy task, but the good news is that there are immediate changes you can make to vastly improve the quality of your résumé, and practice makes perfect. When they first get into my hands, 99% of the résumés I critique don’t work. Here’s why:

1. They don’t sell valuable experience

Most résumés describe positions as though recruiters and potential employers are unaware of what people do every day. For example, if you are a “Sales Manager” you will most likely include functionalities such as “planned and forecasted sales, led the sales team, reported to the Sales VP…”

Every time I read résumés like this, I think to myself: “Really? How can anybody think we don’t know what a Sales Manager does day in and day out? Every Sales Manager in the world does that.” In reality, these statements say nothing about the person handing in the résumé.

Instead, they should be talking about what they have accomplished, and the best way to do so is by measuring their relevant experience. For instance, if that same Sales Manager wrote “increased sales by 80% in 6 months by leading a new team into an unknown territory,” they’d sound much more impressive. I don’t know about you, but I would probably pick up the phone and call that person for an interview.

2. You can’t understand them

I respect the level of technical expertise that certain roles require, and I admire people with deep scientific knowledge. That being said, certain professions need to learn how to write understandable résumés in order to have a better chances of getting hired. If I have a résumé in front of me that is full of technicalities, I have a hard time undering who exactly this person really is, not to mention anything else that goes beyond their technical expertise. Occasionally, I feel that some engineers feel that including more technical terms shows more knowledge, and I’m not so sure about that.

Instead, write a clear, easy-to-read résumé that sells you as a complete professional. Include a section with all technical skills and certifications in which you can list the technical information you have so it is listed on your résumé for the recruiter to find.

3. They don’t position the person

When some people measure their experience, they simply do it in a way in which it doesn’t clearly reflect a picture of them as attractive candidates. And when I say “attractive” I really mean “irresistible”. One thing is to measure the scope of your job, which is necessary, that is, number of clients, type of products, geographical region you served, number of students, etc.

Instead, explain the impact of your performance on business results. Tell the reader what you were capable to change and why they need to hire you and nobody else. People who read your résumé will never guess your value unless you tell it to them, so I encourage you to be clear about it. Tell them why they should hire YOU and no one else.

4. They are not focused and dynamic

Very few people are able to summarize 20-30 years of experience in two pages, as is typically recommended. Most people list way more than they need to, and sometimes go on for three or four pages and then some, making their résumés painfully long and confusing. On top of that, they use the same version of their résumé to apply for every job out there.

Your résumé needs to be dynamic so you can adapt it to the job you are applying for at a given time. You need to give it focus so you can make it applicable to the job you’re applying for with the right keywords. Not all size fits all in this case.

Remember, the interview process is about you selling yourself, and to get an interview is the goal. Your résumé is the first, and one of the most important steps in this process. If you want to appeal to recruiters, make sure you make your experience and personality shine.