Making mistakes is a great way to learn. Making mistakes is also not particularly fun.

It's a lot more fun to avoid them entirely.

Here are some of the most common mistakes entrepreneurs—and businesspeople in general—tend to make:

1. Think of a plan as an end result. Say you’re agonizing over a business plan; somewhere along the way you've forgotten your goal is to actually start the business. Establish goals, create long-range plans, make to-do lists, and get going.

Most successful people are solid planners and excellent adapters. Get started so you can start adapting.

2. Assume style indicates substance. Logos, identity packages, killer wardrobes, eccentric work spaces... none of those matter if you can't deliver. Businesses are built on go, not show. Your business or personal style will create a memorable brand as long as you deliver.

Just be you. And get to work.

3. Think of business as all-you-can-eat. Ideas are thrilling. Opportunities are tantalizing. Dreams are exciting.

Great, but execution is everything. Take on too much and you do few things well. Keep getting distracted by the latest trend and your best ideas get ignored.

Check out everything on the business menu, but only select a few items at a time. Don't be afraid, or have too big an ego, to start small. Small is almost always your start-up friend.

4. Underestimate the time required. Nothing ever goes as quickly as you predict; in a start-up, time passes in reverse dog years. Create timelines but always factor in scenarios and sensitivities. If you don't reach your estimated sales in six months, what will you do?

An estimate is theoretical. Plans are more concrete. Know what you will do if your timelines are wrong. They will be.

5. Assume perfection is required. Trying to create a product that meets every conceivable customer need? Sooner is almost always better than later, so do a Tim Gunn and make it work. Get to market and then start refining your products or services based on actual customer feedback.

6. Underestimate the money required. It’s easy to underestimate cost when you let hope creep into your calculations. A start-up, no matter how bootstrapped, always has unforeseen costs. Just because you really want something to work out doesn't mean it will magically cost less.

Apply sensitivities and create plans in case your estimates are wrong. Just like your time estimates, they will be.

7. Give up too soon. Success rhymes with excess for good reason: Entrepreneurs who succeed do so because they work harder and longer. Before you give up, take a step back and decide whether additional effort is all that's required to overcome roadblocks or hurdles.

Sometimes it's not the business or the market. Sometimes it's you. Never quit until you’re sure it’s not you.

8. Stop acting silly. If you’re like me your favorite childhood stories involve something stupid you did. (How else would I know the right mixture of sulfur and saltpeter will burn hot enough to turn a Tonka truck into a glop of metal?)

Business is serious enough. Every once in awhile, do something silly. Silly is memorable. Silly makes you feel like a kid again. Laughing at yourself will make the toughest day a lot easier.

9. Adopt expectations. We are all influenced to some extent by what other people think about us. But what do you want? What really matters to you? Live your life based on the opinions of others and you live their lives, not your own.

What matters most is what matters most to you. Always be sure you're living your life. It’s the only one you get.