It may seem straightforward at first—even simple. The application's instructions are clear: In order to be accepted into TechStars, the prestigious accelerator program, start-up founders are asked to submit two videos—one to describe the company's product or service, and the other to introduce the team. (We've asked the 2012 teams accepted into TechStars to hand over their videos—you can find a selection in the video player above, and also later in this article.)

"Production value is not important to us," the TechStars application reads. "It can be quick and dirty."

And yet, speaking to founders, one gets the sense that making the application video is all but quick. Dirty, maybe, but when it comes to putting together a three-minute video many founders struggle.

So, what exactly makes a good team video? We asked the experts. David Tisch, the managing director of TechStars NY, and David Cohen, who founded TechStars and serves as the accelerator's CEO, tell me they've watched about 10,000 application videos. At this point, it's safe to say they know what works—and what doesn't.

"When I watch a video, I'm thinking, 'Do I want to know more, or do I want to stop here?'" says Tisch.

"Why should I be excited about it if you're not?"

One of the quickest way to lose a viewer's interest, especially in the team video, is by ignoring the obvious: Film allows founders to show off their personality, and offer a slice of who they are as person.

"The text [application] is boring and there's no life in it," says Tisch. "It's hard to show life in text. So when you get on video it's easy to show personality and to show energy, and I think the first mistake people make is they're low energy, or not interesting. On a team video you have an opportunity to stand out. Not doing that is a fatal flaw, that is, when you're talking about what you're working on, and not being excited about it. Why should I be excited about it if you're not?"

Ninety percent of language is nonverbal, adds Cohen. "It's the emphasis of the way you say it, the look on your face," he says.

For Cohen, a team video should explain why, out of a million possible business plans, the founders have located this problem as the problem they want to solve. "I want to understand the source of your passion," he says.

Pronouns matter.

When Tisch invests in start-ups, he invests in the people, not necessarily the idea or business, so it's essential to explain precisely how the team functions. What are their relationships based on? How do they plan to divide up responsibilities? Essentially, Tisch and Cohen are curious to see how a team gels.

"If it's a three- or four-person team, and the lead is not sharing the joy with the team members, it's a mistake," Tisch says. "It doesn't need to be equal. But you're team of four—not one. I'm looking out for the use of the word 'I' or 'my' versus 'our' and 'we.'"

Take, for instance, the team video of the founders of Moveline, a moving logistics company. The video is fairly barebones: Founders Fred Cook and Kelly Eidson appear in front of a webcam. They list out, to an almost self-deprecting degree, all of the reasons why Moveline wouldn't work. It's funny, it's counterintuitive, and it worked. Moveline was accepted into TechStars New York.

"They want to know that the people coming in are real people and have some chemistry with each other and can see working them," says Fred Cook.

"We laugh at the same jokes at the same time, which wasn't scripted, but that's probably the strength of our video," says Kelly Eidson.

"Better to be cocky and arrogant than to be meek and humble."

Some founders may be concerned with the intersection of confidence and arrogance. After all, you want to be assertive that your business can become huge, but you have to be humble that it hasn't achieved all that much yet. So where do you strike the balance?

"I'm a little OK with arrogance," says Tisch. "You need a swagger as a start-up founder. You'll need to hold your confidence. I don't dislike arrogance."

Cohen agrees, but insists that the team must be likeable, and must be able to do something that will help them stand out.

"The ones that are fun are the ones that do something a little different," he says. "You remember them. Maybe it's a little joke."

Take Diego Zambrano, the founder of Bondsy, for instance. If you've seen Zambrano recently, you'll likely remember a most prominent facial feature: a ZZ-top-like beard that descends down to his sternum. When it came to making a video, Zambrano embraced his beard, adding subtitles detailing how long he's been growing his beard, and how often he cleans it. (Three years; daily.)

"I have this look that doesn't quite fit as a CEO," Zambrano jokes through his Brazilian accent. "Because I have this personality, it makes sense for me to use it. But maybe not for others. For others, it may make sense to highlight other assets."

Getting a personality across speaks volumes, he adds, for one very obvious reason: "At TechStars, sometimes your idea can change," he says. "But if you're a great person, someone who is flexible, they'll want to work with you."

Length of the video can be crucial, too. Though the video can technically be up to three minutes, Tisch says it's foolish to make it that long. 

"Two minutes is ideal," he says. "Three minutes means you're insecure. If you can nail what you're doing in a minute, I think that's super powerful."

Product videos should be about the benefits, not features.

Although product videos can seem fairly straightforward, they're easy to get wrong, says Tisch.

"The worst thing to do is feature walkthrough," he says. "The best thing to do is benefit walkthrough."

What he means is that entrepreneurs will often explain how exactly a product works, but will sometimes forget to explain how these features are necessary, or solve a big enough problem.

"If you're showing me features, tell me why they're important, not what they are," he says. "I think that's a huge thing to tweak to take it to the next level. It's easy. Instead of telling me what it is, tell me why it's there and who it's helping. I think that's the difference between an "Oh my God" product video and a good one."

Ultimate goals of a video: Be unique. Be confident. High energy.

In the end, the videos should showcase why your start-up is unique, why you're so personally tied to the success of this company.

"I'm looking for teams that I want to work with," says Tisch. "I'm looking for teams that are going to win that idea. It's not about betting on the right idea, it's about betting on the right team for that idea."

Succesful founders echo this idea.

"They don't want someone who is going to drop the idea if they don’t get into TechStars," says Katrina Brickner, co-founder of Droptype. "We were actually going to move to New York whether we got in or not. It's about showing that confidence."