I teach and mentor others in a tongue in cheek manner on the topic of: How to Destroy Your Business in 5 Easy Steps.
The first agenda item I always speak of is hiring the wrong people (including the wrong recruiter). If you hire the wrong person, step 2 (training) is set up for failure as are the remaining steps.
Even the most qualified candidate must match with the organization culture. A happy employee is a productive employee.
If he/she is not happy - the success of the position is destined for many bumps, bruises and set backs throughout the employees tenure. So while time to hire is so very important these days, hiring the right person rather than filling the position is so much more important to organizational health.
Hire an insanely motivated candidate who fits the culture and has the basic skills necessary. Train them. Reward them. Hold them accountable. Discipline when needed - turn them loose when necessary.