This is a sore spot for me considering I've applied for hundreds of jobs over the last 10 years, had dozens of interviews, and only been hired for 2 (and then been let go from & moved away from).
I do a lot of the same things Jennifer does: researching the company prior to applying, reaching out to people within the organization if I know them or someone I know knows them, rewriting my resume & cover letter to highlight the experience they're looking for, following up via email on my application. If I'm able to get an interview, I do research on anyone who might be interviewing me, Google to see if there are some standard questions the company always asks, go on Glassdoor for anonymous reviews & salary ranges, and sometimes practice aloud.
It's incredibly demoralizing & frustrating overall.