1. Make friends with people at work 2. Eventually, some of those people will get new jobs, and they can refer you to their new employer (and vice versa). 3. Repeat for a few cycles and you have a network full of potential job opportunities without ever going through a job board.
I haven't bothered with non-word-of-mouth jobs for over ten years. If the job's not recommended to me by someone I already know, I'm not interested. It saves sooo much time.