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The 5 big mistakes an entrepreneur can never make

CNBC's 'DON'T' guide for entrepreneurs

Ever wonder what it takes to be your own boss?

Sometimes it's the "don'ts" rather than the "dos" that separate successful businesses from big failures—failures that could have been avoided, too.

Many young entrepreneurs, without realizing it, harm their chances of growing a successful business; they think they are following the right advice, when they should be doing the exact opposite.

CNBC has come up with a "don't" guide for entrepreneurs, to help them avoid five big pitfalls that can make a good business idea crash before it even gets off the ground.

1. Don't give a $#*!—Get out there and sell!

Heidi Roizen, operating partner at venture capital firm DFJ, said the most important lesson she passes on to entrepreneurs is the 20/40/60 rule, which she learned not from a tech guru but from another California icon: actress Shirley MacLaine.

"At 20, you're constantly worrying about what other people think of you; at 40, you decide you don't care what other people think of you; at 60, you learn that no one was actually thinking of you. It's been a guiding light for me," said Roizen.

2. Don't be a serial offender.

Since it's difficult to start a business by doing just one thing, entrepreneurs should avoid the trap of consecutively producing, marketing and selling. It is necessary for them to do all three at the same time. Thinking in a chronological order is prohibitive to growth.

3. Don't "mirror hire."

If you are good at numbers, you should not focus on hiring someone who is also quantitative. Instead, you should hire a good salesperson who has a different skill set and can pick up some of your slack. You may not have the most in common with this person, but then again, building a business is not about getting along with everyone.

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4. Don't scale too fast. You've got time!

There is a common misconception that entrepreneurs should scale their companies quickly in order to stay afloat. Remember, rarely do start-ups fail because they can't scale their business fast enough. Selling product should be the No. 1 priority for new entrepreneurs. Scaling up will then come at a natural pace.

5. Don't focus on the "1 percent."

Even though self-starters believe their target is typically 1 percent of a global sector, it is important for entrepreneurs to estimate their own sales rather than a slice of a total market. Ditching top-down math for a bottom-up calculation is a key component on the road to business success.