Not using proper spelling and grammar
This is the absolute biggest mistake you could make. Spelling and grammar mistakes are the simplest to correct; therefore, a resume filled with these types of mistakes communicates to the hiring director that you didn't take the time to look over your final draft. In fact, many hiring directors will not even call someone in for an interview if they find a spelling or grammar mistake in his or her resume. That's how important it is to proofread meticulously. A perfectly proofread resume communicates that you care about your career and the job that you are applying for.
To avoid spelling and grammar mistakes, you should get a couple of fresh sets of eyes to look over your resume and give it a good proofreading. Whether they are your family or friends or professionals at a resume writing service, you should always get other people to look over your finished resume to check for mistakes.
Not being consistent
Another group of simple mistakes that are common in resumes reflect a lack of consistency. These types of mistakes include using mismatched font sizes, having incorrect date alignments, and using periods in one set of bullet points but not in others. When formatting your resume, be sure to check for inconsistencies such as these. Resumes lacking consistency look sloppy and unorganized, and the people looking at your resume will label you with those same characteristics.
When applying for jobs, it's important to remember that hiring directors will judge you based solely on your resume. Your resume is what will get you interviews. Therefore, you need to spend some quality time on it, making sure that it is professional-looking, organized, and formatted consistently.
Not providing enough/providing too much information
You should be careful to include enough of the right kind of information and exclude the wrong kind of information. When it comes to creating resumes, some people get this backwards and end up including too much of the wrong kind of information. For example, employers do not need to know about your personal interests, such as cooking, karate, or your membership in the National Elvis Lovers Association. Instead, include more details about your accomplishments, duties, school activities, etc.
Not using the resume format that works best for you
When formatting your resume, there are two basic approaches you can take: chronological and functional. Since both are very different from each other and are used for different purposes, choosing the wrong format could greatly hinder your chances of landing an interview.
For example, a functional format, which puts your skills and achievements above your job experience, is best for avoiding repetition in job duties and for communicating that you would like to transition from one career to another. This format also works well if you are applying for a variety of different jobs that require different sets of skills.
On the other hand, a chronological format lists your work experience first, in reverse-chronological order, with your most recent job at the top. This format is best for showcasing where you have worked, displaying your titles, and/or demonstrating longevity at a company.