When you advertise for a position, you're going to get a lot of garbage resumes. It's a given. Throw them out. If they don't look good on paper, they won't look any better in person.
We have specific job descriptions and qualifications for each position. If somebody isn't qualified for a job, they won't be considered. We have empowered our office manager to do the majority of the interviewing and hiring. We (the three docs) have an opportunity to meet (briefly) everyone who interviews during the office walk-around. They also get introduced to the staff. We always get everyone's input after a promising interview. We always call references. Still, you never really know what you're getting until the employee reports to work.
It's understood that the first 90 days is a probationary period. If someone's not working out, they usually don't even last that long. Labor laws differ from state-to-state, but in my state we're able to terminate an employee without cause. We always make sure we're taken steps to document deficiencies and counsel/remediate them appropriately, however.
We have worked hard to create an environment where our staff enjoys work, gets along well, helps one another, etc. They're a great team. Hiring a new employee into an environment like ours is something of an acid test...when somebody fits in, you can just tell. When they don't, it's equally apparent.