Do not start writing the resume until you have any idea about the employer. Also, you should remember this important point: you need to show the employers what you can benefit them but not what you may benefit from them. The perfect resume must focus on the strength in necessary experience and skills that the employer may require from you. You will score more point with your knowledge about the employers and understanding of what they expect from you.
Before writing a resume, you should spend time find out carefully about the employer. The more you know about the job and the company, the more suitable your resume and resume may be to the job requirements and as a result, the more your chance will be.