Unfortunately there's no crystal ball you can consult to make sure that you're hiring the right employees. The interview is the best insight you're going to get, so you need to make sure that you use the time wisely. If you aren't hiring exceptional people, it might be time to re-evaluate your interview process. Remember, this is your one opportunity to make a decision on whether or not this person will not only be a good fit for the position, but an asset to the company as well.
Every company is different, but there are some good strategies that can be useful for almost everyone. To start, make sure you screen all resumes and have someone conduct a brief phone interview. This provides a bit of insight into items including responsiveness and ability to communicate over the phone, the candidates actual interest in the position and any due diligence the prospective employee has completed thus far. It's also a good idea to ask for a writing sample. It can be on any topic, and it doesn't have to be long, but it will provide you with excellent insight into the person's ability to communicate on paper. Communication and writing skills are valuable in almost every job, and they are also very difficult to teach. Once you decide he/she is a good candidate, it's time to schedule an in-person interview.
Structure your interview in five parts: introduction; job history; future goals; why this position; and have they done their homework. Remember, you're looking to see how this candidate will fit with the current position as well as possibly promoting within your company in the future.
Bottom Line:
An interview is your brief window of opportunity to select employees that will hopefully contribute to the growth and development of your company over time. Use your time wisely to ask important questions and truly measure the person's skills and attitude with not only the current position but your company's culture and future.