But it may come as a surprise to you that the single most important thing you can do to land yourself a job has to do with a tiny, often-missed question found on many organizations' job applications: “Were you referred to XYZ Company?”
As a recruiter, there have been countless instances where a candidate who fell short of the required qualifications for a job was phone interviewed simply because he or she was referred to us by someone in our organization.
This practice isn't only important to recruiters. It's good for all parties. Referrals have great conversion rates from hire to tenure and generally improve the quality of hire.
While it may not be possible to only apply for jobs where you have a personal connection, I recommend the majority of organizations you use are ones with at least a second-degree connection.