The greatest killer of startups is bad hiring.

Ask any major investor and they will tell you that the costs of bad hiring decisions - and taking too long to realize them - routinely kill off their portfolio companies.

I've spent a lot of time watching my best CEOs hire and retain talent and these are five important techniques I have picked up from them, that work, and that are translatable across different businesses.

1) Look for Confidence but Openness

The best leaders strike a balance between very confident and willing to defend their vision and understanding that they can't see every angle and should be willing to validate different ideas and accept coaching. A confident person who cannot accept coaching or change dogma is a narcissist and those are the worst killers of any team.

2) Look for Failures Leading to Successes in Their Career Experience

My old boss had a saying: "a person who has never failed is destined for failure." Every successful person I have ever met has had multiple failures in their career. But they use these failures as learning experiences and should be able to tell you very specific career learning for each of them and how it informed their next experience. If that learning is evident and the next experience was a success, that shows they learn well and could be a great addition to your team.

3) Look for Small Teams Experience Before

True big corporate cogs almost never adapt well to startup environments. As such, career experience within a startup, especially a successful one, is a major plus. But, that's not always present so one other way to screen for this is to look for small teams experience inside larger companies. Did they run a specialized sales team of 5-10 people inside their larger company, for example? Have they ever been part of a "startup within a larger company?"

4) Check More References Than Just What They Give You

In the social era, particularly with Linkedin, you should no longer have to rely on a couple references they put on a page. Make sure to call several of their career stops and hear different impressions. No one will have a flawless record when you do this (God knows, I can think of a few bad calls on my resume!) but you will get a more complete picture. And if just one or two bad ones stand out against the rest and the specific criticism is not spread across, then that's okay and you probably just don't the whole story.

5) Try Before You Buy

The best CEOs are ready and willing to pull the trigger but they leave themselves a fail fast opening. The best strategy is to cliff your hire's compensation, especially equity or options and warrants, so if it's not working after two-three months, you can cut bait and save yourself a lot of extra hardship.