The best way to increse your chances of getting a job is reference. Many large companies advertise their jobs for the sake of fulfilling the conditions of law. However they prefer a new employee being referred by someone already working for them. This is a good for the company. Before the interview they know about the candidate. they can spend less on the ad campagin.
Infact some companies reward the existing employees if their referals make it.
So Next time you find a suitable job, Just dont apply it immidiately. Try to find if any of your friends or aquittances working for that company. Networking helps you to get this information. When you find the information fo your aquittances , you have an insider information on what the company is exactly looking at, how is the company, work culture of the company, etc. now make sure that your profile matches their actual need, tweek it if need be and send it thorugh this reference. This way you are bypassing the step one of by passing the stack of resumes. Your resume has a reference whom the company knows. Yoru chances of getting an interview call increse by atleas 50 percent.
Please make sure that the reference you are choosing has a reputation in the company which helps you. also, your reputation with this person is also important.