Many business failures could have been avoided. There are common mistakes repeated time and time again, so why not learn from the experience of others? Given that 80+ percent of small businesses close shop in less than two years, the odds are already stacked against you. But you can change that.

Here are a few first-hand accounts from the people behind self-proclaimed failed startups. Find out what went wrong, how it could have gone differently, and lessons you can take from their wrong moves.

1. Dan Greenberg of Sharethrough 

Greenberg learned that focus is key, and that "center of gravity" needs to be at the crossroads of passion and problem solving. He co-founded Sharethrough with the intent to "modernize Internet with meaningful content" while sidestepping ads that are too obvious. However, he readily admits that the company had no focus and was all over the place, finally leading to a few very tough years of chaos.

2. Evan White of Evan White PR

White says he was thrilled when he secured his company's first stakeholders--so happy that he failed to have a written agreement with them regarding where the company was headed. He suggests making sure everyone is on the same page before moving forward. Everybody in the company had different visions and goals--but didn't figure that out until it was too late. There's always time to make a business plan.

3. Caroline Ghosn of Levo League

"Trust your instinct," advises Ghosn, who wishes she'd followed her own advice. She admits she got caught up in the "noise" that distracted her from her entrepreneurial efforts. Instead of working on learning from mistakes early on, she dwelled on the failures, which trickled down to her customers. "I'm growing more attentive to my first instincts," she says, but it's still human nature to go full-speed ahead when your gut is telling you otherwise.

4. Shane Snow of Contently 

Building a solid team instead of doing it as a one-man show is the best advice Snow can give. This can be difficult for overachievers and those prone to micromanaging. However, Snow reminds entrepreneurs that nobody is the "best" at everything and it's all about finding partners with skills and characteristics that complement (rather than replicate) your own. This means investors, communities, business partners, and advocates.

5. Carrie Kerpen of Likeable Media

Kerpen's No. 1 piece of advice is to be as adaptable as possible. While she stresses making solid plans, it's also crucial to remember they don't always work out. Business owners and entrepreneurs need to roll with the punches and learn lessons from each stumble. There's no room for stubbornness, and that's a self-defeating trait for any business owner.

Nobody is a natural-born entrepreneur: It's how you handle challenges (and how much preparation and research you do) that can help you be successful. There's a very good chance somebody else has already made the mistake you're about to make. Why repeat it when you can learn from it right now?