You can find a thousand articles online about what job seekers should do to prepare for an interview. But founders, executives, even middle managers often forget that an interview isn't a one-way street. The interviewer needs just as much preparation to land the right candidate.

I've been interviewing people and observing interviews for more than 40 years. And when I think about whom I'm going to hire, I don't think about the person as a short-term investment. Most decision makers think only about how much they're going to pay a new hire per year, and that's how they determine the person's cost. But what about over five years? Or 10 years?

This is an example I use in my book, All In. When you hire someone at $50,000 per year, you have to assume the person will be with your company for a decade. And if that person is, it means you're going to end up paying him or her $500,000. 

Treat someone's interview with that in mind: "Is this person worth half a million dollars?"

If you want to find the right employees for your company, you have to put in place protocol for preparing for and conducting interviews. 

Here's what you need to know to get started. 

1. Have a clearly defined position analysis and ideal candidate.

You want someone with great experience and qualifications. Some impressive credentials may be a nice addition, but you won't find the perfect candidate without clearly defining the position and the candidate you're looking for.

You should know exactly what the position entails and what the employee will be doing every day, so you can choose a candidate whose attributes match up perfectly with the role he or she is filling. Think about former employees who held the position you're looking to fill--and what made them successful (or why you had to let them go). Talk to the manager who'll be in charge of the person you're hiring. Ask the manager what skills and experience the ideal candidate would have. 

Do your due diligence internally, so that you aren't just filling a role.

2. Narrow down the candidates using a 20 to 30 minute phone interview or video call. 

You don't need to interview every candidate in person. 

Face-to-face interviews can be costly and time intensive for your managers. Instead, use phone interviews as a way to weed through the bad candidates. You can do this with a few basic questions--like whether they truly have relevant industry experience.

When it comes to hiring, the most important measure is to make sure the person on the other end has the knowledge and expertise that meet your standards. If someone doesn't sound impressive over the phone, then consider skipping the face-to-face interview. 

3. Develop the right questions for the position. 

Every candidate with half a brain walks into an interview knowing his or her biggest strengths or weaknesses. These are rehearsed responses--which means it's your job to find ways to move past the façade.

One of the things I like to do is ask questions that get candidates talking about someone else, instead of themselves. Ask them about their last supervisor and see what they let slip. Ask them to talk about their former team members. You'll get to know them better when they're speaking off the cuff, which will give you a good sense of what sort of person they are.

Remember, your job is to get applicants out of their spin zone. They've been preparing for this interview, just like you. 

4. Make sure the setting is conducive to holding a good interview.

Neither you nor a candidate is going to learn much about the other if you don't have a distraction-free place to hold the interview. 

Take the time beforehand to make sure you have a conference room, an office, or somewhere quiet and out of the way that you can hold the interview. 

Not only do distractions and interruptions break up any conversational flow, they also make your business look disorganized and chaotic to the applicant.  

5. Have a plan in place for the interview.

I see interviewers make a lot of mistakes that come from a lack of planning and awareness during the actual interview. 

Sometimes, I see interviewers ask several applicants different questions when they're all applying for the same job. Afterward, the interviewers are left scratching their heads because they don't have a benchmark to measure the candidates against one another. 

Other times, the interviewer won't stop talking, and the candidate hardly gets to say a word. The manager talks the entire time. Then the interview ends, the applicant walks out, and the manager turns to me and says, "I really like them!" 

That's when I ask, "How would you know? You did all the talking. All they had to do was nod their head and ask how much the job pays."

The bottom line is that the employees you hire are only going to be as good as your interview process. Put a plan in place, and make sure it's followed for every interview.