Do these things once, but do them very well. If you knock these out of the park at the beginning, you’ll save yourself a lot of heartache later in the process (you’ll probably get a job sooner, too!).
Before you start the process, make sure your tangibles are pristine. Recruiters read hundreds of resumes and cover letters each day, and if you’re the only one with a typo in your ‘experience’ section, guess which resume is going in the trash? Have a few developer friends look over your resume and take their feedback very seriously. It’s important to do this now before you’ve sent 50+ wasted applications.