Jack Kelly is CEO, founder, and executive recruiter at one of the oldest and largest global search firms. According to Kelly, during the course of his 20-year-long career, he has reviewed more than 480,000 résumés and LinkedIn profiles--or an average of about 100 a day. 

Needless to say, Jack Kelly knows what makes a résumé and LinkedIn profile great, and what makes it not-so-great. The trouble is, says Kelly, job candidates who should know better "tend to sabotage their résumés and LinkedIn profiles with rookie mistakes."

The good news is that anyone can immediately improve their résumé or LinkedIn profile. Here, according to Jack Kelly, are 18 things you should remove from your résumé or LinkedIn profile right now:

1. Trim down your detailed work experience. When it takes too much time to read what exactly your role was, it's unlikely people will read it at all. Cut down, bullet point, and paraphrase to brief perfection. Says former Google executive Laszlo Bock, "Once you're in the room, the résumé doesn't matter much. So cut back your résumé. It's too long."

2. Delete jobs older than 10 years ago if possible. Unless an older position is particularly notable--maybe you were a company's youngest executive, or you saved your company billions of dollars--then just let it go. 

3. Update your résumé and LinkedIn profile before you go on an job interview. Get rid of all the old, out-of-date info, and bring in the new. Remember: You only have one chance to make a first impression.

4. Drop the hobbies and other superfluous things. Don't list hobbies on your resume--save these for interview conversation. And any awards you list should be from community service or previous work.

5. Remove mentions of your kids' achievements. I'm sure your kids are great and all that, but they have nothing to do with you finding your next job.

6. Delete the "Objective." Instead of describing what you are searching for--the "Objective" section of a resume--tell the prospective employer how valuable you can be to their company in your professional summary.

7. Lose the silly email address. If you're still using an old, seemed-appropriate-at-the-time email address--kooldude86@yahoo.com--it's time to create a new, more professional one.

8. Still have a fax number in your résumé? Dump it. Quick. I suspect that very few companies even know what a fax machine is anymore, much less actually have one.

9. Ban the corporate buzzwords and jargon. It's bad enough hearing those buzzwords from current coworkers. A recruiter doesn't want to hear even more of them from you.

10. Devote less space to shorter-term jobs than to longer-term ones. Jobs you held for just a short time deserve far less emphasis than ones you held for 5 years or more.

11. Drop jobs that you had for less than six months. However, do be sure to include them when you fill out an application for a position. You should have no gaps in your experience.

12. Don't be overly clever or too creative for your own good. Make your résumé or LinkedIn profile easy to read and relatively conservative--unless you're specifically looking for a job in a field (graphic design, for example) where you're expected to show your stuff. Laszlo Bock suggests black ink on white paper with half-inch margins, and aligned columns with consistent spacing.

13. Delete political volunteer experience and affiliations. It's no secret that politics is a landmine just waiting to be stepped on--avoid potentially turning someone off before you even have a chance to interview with them.

14. Remove mentions of very basic computer skills or superficial knowledge of a foreign language. You don't want to fumble if someone tests your knowledge in an interview--and there's a good chance someone will.

15. The fact that you know how to post on social media such as Instagram and Facebook should be deleted. This is pretty much something even 5 year olds know how to do now. However, if you're a social media and/or SEO expert, then by all means include that.

16. Remove any falsehoods or exaggerations. There are a lot of things you could lie about on a résumé or LinkedIn profile, or exaggerate: work experience, college degrees, GPAs, sales results. Says Laszlo Bock, "Putting a lie on your résumé is never, ever, ever worth it. Everyone, up to and including CEOs, gets fired for this."

17. Lose anything that would indicate what your age is. For example, leave off graduation dates. Age discrimination does exist, and you at least want to get your foot in the door for an interview so they can see how awesome you are at creating age-irrelevance.

18. Fix typos and grammatical errors. According to a CareerBuilder survey, 58 percent of résumés have typos. Misspelled words and poor grammar are total job-possibility killers--proofread several times and have others proof for you. Laszlo Bock suggests this additional pro tip: "Read your résumé from bottom to top: Reversing the normal order helps you focus on each line in isolation."