Some of the most successful entrepreneurs in today’s business world started at a young age. Silicon Valley is filled with 20-something founders hoping to grow their startups into the next global phenomenon.

As a result, entrepreneurs are starting their own businesses earlier than ever before. While this can be a good thing, it has also led to more than a few unnecessary failures. In some cases, the timing of the idea wasn’t quite right. But in many cases, company failures are more closely related to missteps on the founder’s part. Here are nine common mistakes that any entrepreneur should avoid in starting a new business:

Failure to plan
When an entrepreneur sets out to start a business, but doesn’t even have an idea yet, he’s already committing his first fatal mistake. The idea should come first, followed by the determination to form a business around it. Merely starting a business for the sake of being known as a “startup founder” is usually a direct route to failure.

All talk, no action
Many people know someone who seems to have great business ideas, but never follows through on any of them. You’ve possibly been stuck talking to a person like that at a networking event. Don’t be that guy. Instead of putting your energy into telling the world about your great idea, use it to actually make a business out of that idea.

Never asking for help
Even the most hard-working entrepreneur needs help getting his idea off the ground. Whether it means outsourcing administrative tasks to online freelancers or seeking the advice of a mentor, it’s important that founders get help while building their businesses. Trying to do it all alone means you’ll spend far too much time on activities that aren’t as effective in helping the company grow.

Impatience
Building a successful business takes time and, along the way, there will likely be instances when failure seems certain. Entrepreneurs who succeed have the patience necessary to keep pushing through those long periods of non-growth and eventually find success. Experienced business owners realize that it may take several failures before a product change helps it find an audience and achieve success.

Hiring friends
Some of the best startups began as a joint venture between friends. As inspiring as those stories are, when an entrepreneur hires his friends, he often overlooks necessary skillsets in favor of working with someone he already knows. Friend or stranger, entrepreneurs should carefully review resumes and choose new team members based objectively on factors like skills, abilities, and culture fit.

See also: Yes, it’s Okay to Ask for Help When Starting a Business

Forgetting about the customer
It’s all about the customer. Whatever product or service you’re working hard to bring to market, if you forget that fact, you lose sight of what’s important. A successful entrepreneur always puts the customer first, developing and refining his product based on the feedback he gets from customers in his target demographic.

Fearing theft
In today’s competitive marketplace, ideas can often seem like hot commodities. Many founders are paranoid about letting others know what they’re planning because they’re sure someone will steal the idea and use it to form a competing business. This fear can hold a young entrepreneur back from essential steps in early-stage startup efforts, including testing the product or seeking funding. Chances are, your business partners, potential investors, and friends won’t want to put the effort into starting a business based on your idea, so don’t let fear keep you from telling others about your great new venture.

Lacking sales ability
You can have the best product or service on the market, but if you can’t convince others of that fact, you won’t get far. The ability to pitch your ideas and conduct interesting, effective presentations is essential to growing your business. If you’re uncomfortable with this aspect of business ownership, consider joining a group like Toastmasters or taking a college course in public speaking.

Perfectionism
No matter how much time and effort you put into your business, it will never be perfect. There will always be small improvements you can make or bugs you need to fix. Instead of spending years refining your product, set a hard-and-fast launch date and force yourself to stick to it. Conduct thorough user testing to make sure your offerings are ready to launch and accept the fact that you’ll likely spend the days following your launch making slight tweaks.

For young entrepreneurs, the market is wide open for great business ideas and innovations. By avoiding common mistakes and pursuing your goals passionately, you can form a successful startup at any age.

A journalist and digital consultant, John Boitnott is an advisor to the Startup Grind community. He’s worked in TV, newspaper, radio and Internet companies for 20 years. He has written for Fast Company, NBC, Inc.com, Entrepreneur, USA Today, Business Insider and Venturebeat, among others.

Read all responses to the Entrepreneur Insider question: What are some common mistakes young entrepreneurs make?

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This is where most startups go wrong by Stephen Lake, CEO of Thalmic Labs.

Doing these 3 things will destroy your startup by Michael Gasiorek, editor-in-chief of Startup Grind.

The avoidable mistake every entrepreneur makes by Andrew Filev, founder and CEO of Wrike.