Directly soliciting citizens as potential recruits isn't exactly a groundbreaking new strategy. For decades, departments have put recruiting booths/tents at community events, festivals, parades, and job fairs. Any measure of success for this sort of effort is anecdotal at best.
Conversely, one measureable strategy for filling the ranks is to invest agency resources into developing young people for the job. Specifically, capital spending in cadet academies, Explorer groups, and summer internship programs—while costly in terms of both time and money—can yield quantifiable results.
Through these job-specific programs, young people interested in the law enforcement profession are given a fantastic introduction the inner-workings of police work. Each agency conducts these efforts differently—depending on available monies and personnel, and the complexity of the program—but most share somewhat similar components.
For example, cadet, Explorer, and internship programs almost always incorporate some level of education on the mission and objectives of law enforcement. Each emphasizes the importance of character development, physical fitness, good citizenship, and civic duty. Each involves some level of volunteer work such as traffic/crowd control at local events.
Most programs have specific age and academic requirements (typically kids age 14-18 with at least a 3.0 GPA) as well as passing marks on physical fitness tests and criminal background checks.