9. Visually Too Busy
If your resume is wall-to-wall text featuring five different fonts, it will most likely give the employer a headache. So show your resume to several other people before sending it out. Do they find it visually attractive? If what you have is hard on the eyes, revise.
10. Incorrect Contact Information
I once worked with a student whose resume seemed incredibly strong, but he wasn't getting any bites from employers. So one day, I jokingly asked him if the phone number he'd listed on his resume was correct. It wasn't. Once he changed it, he started getting the calls he'd been expecting. Moral of the story: Double-check even the most minute, taken-for-granted details -- sooner rather than later.