A well written resume is usually one or two pages long. Nobody reads more than that anyway. For people with a lot of experience, it may be hard to fit everything in two pages. Most resumes can save a lot of space by avoiding a few unnecessary things:
1) Personal information. Use only business related data. Avoid listing your social security number, birthday, age, marital status, sexual preference, family information, not relevant to the job hobbies, etc. Besides saving the valuable space on your resume, it will help you to keep your identity protected and prevent employers to make their decisions (discriminatory or not) too early. However, don't forget to mention your contact information (in most cases phone number is a must, as well as, your e-mail).
2) Listing every job. The pizza delivery job that got you through college should not be on your resume unless it’s relevant to your current job search.
3) Listing every education. If you have a graduate degree, it’s a given that you have a high school diploma - leave it off.
4) Personal pronouns (I, me, my) are redundant as the resume is all about you anyway. Also do not refer to yourself in the third person (e.g. "He performed..." or "John has experience..."). Instead, start sentences from "Performed...", "Managed...", "Worked...", etc.
5) Providing references or stating "References available upon request." You don’t want your references being called before you have a chance to let them know. Don't mention it at all - it's a given and will be requested from you if you're seriously considered for the position.
6) Abbreviations and acronyms (unless they are commonly recognized). Using too many of them can make your resume unreadable.
7) Using e-mail address that looks unprofessional. It is also not a good idea to use your current employer’s email. Get a free account from Google, Yahoo, etc.
8) Objective statement. If you choose to include it on your resume, it has to stand out and be well written statement, not something like "I want a job." Focus on what you can do for the employer, not what you want from them. Don't forget to update it each time as it has to match the position you're applying for and the objective of the company. Because it usually has to be specific, you may want to consider moving it to your cover letter instead.
9) Reasons why you left - do not lower your chances and save them for the interview. Though you may want to put a short explanation if your resume looks like you have been job-hopping.
10) Photos. This may vary from country to country. In the United States it's irrelevant and rather shows that the candidate is out of touch with the process. If you have to attach your photo, make sure it looks professionally.
11) Rather than listing responsibilities, tell about your accomplishments and focus around STAR: Situation, Task, Action, Result.
12) GPA - leave it off, especially if it's not the highest one.
13) Carefully mention soft skills like motivation, attention to detail, problem solving, etc. No one is going to say that they don't have them. Maybe you should utilize valuable resume space for more relevant information.
Before e-mailing your resume, give it an appropriate name, e.g. First_Last Name_Resume. This will save the employer's time of having to rename the file for later reference.