Even the smartest small-business owner can do dumb things now and then. Unfortunately, some mistakes can kill a company.

Just ask Jeff Seifried, small-business coordinator for the City of Aurora, Colo., and Peter Tourtellot, chairman of the Turnaround Management Association. They, along with other experts who prefer to keep their observations anonymous, have seen the best — and worst — of small-business operations.

Here are 10 examples of common, but potentially deadly, errors committed by otherwise brilliant small-business owners. Don’t make the same mistakes.

1. Underestimating the importance of cash-flow management. Two woodworkers had a thriving business building interiors for retail stores. They did beautiful work and their customers were pleased, but it often took them 60 or even 90 days to pay the bill. Until the money rolled in, the partners couldn’t start on the next job because they couldn’t buy materials. They lost jobs because customers were in a hurry. You can be making plenty of money, but if cash isn’t arriving in time to meet payroll and buy inventory when it’s needed, you can be quickly out of business.

2. Getting sloppy with recordkeeping. The owner of a lawn service was haphazard about recordkeeping. If he had kept better track of lawns mowed, he would have known that his oldest mowers had so many miles on them, they were unlikely to last the season without an overhaul. Instead, it came as a very unpleasant surprise when three of them burned up in one week. Good records are a key decision-making tool. If you’re not keeping good track of your business, you are denying yourself the tools to make good business decisions.

3. Ignoring inventory. The owner of a business-supply store bought a flat of construction paper just before school started. Three years later, employees were still stepping around the boxes to get into the storage room. If you end up with stale inventory, discount it and get it out of there. Otherwise, you’re just tying up money and taking up storage space.

4. Neglecting collections. A dentist had dozens of outstanding bills for routine and special dental work approaching 180 days old because his assistant hated to make collection calls. Nobody likes to dun people, but unless you have a systematic collection plan and make sure it’s carried out, some people just won’t pay.

5. Disregarding employee concerns. The owner of a small jewelry manufacturing operation refused to pay overtime. He thought workers should be able to get the job done in the time allotted. Employees came and often left unhappy over what they saw as unfair treatment. Finally, one of them complained to the state division of wage and hour, which launched an ugly and (for the jeweler) expensive investigation. If you have a hard time hiring and retaining good employees, your business is doomed. And if you find yourself the target of an employment-related lawsuit, your expenses can be astronomical. Get expert advice on human-resource issues. While it may look expensive, it can save you a bundle in the end.

6. Failing to delegate. A baker thought she was the only one who could make the perfect cookie. Back trouble that put her in bed two weeks before Christmas nearly shut down the business. Recognize that you can’t do everything. Turn some of the job over to the best assistant you can hire and trust him to do the job, even if he makes a mistake now and then. If you insist on doing it all yourself, you can’t grow.

7. Offering something the customer doesn’t want. A water ice vendor spent all his time and money developing 100 delicious flavors. The trouble was nobody bought anything but cherry, lemon and vanilla. Ultimately, his inventory melted away and so did his profits. Market research is vital. Talk to potential customers, talk to current customers and respond to what they tell you.

8. Letting costs get out of control. The owner of an auto body shop was having such a great year, that he bought a lift that wasn’t in his budget. He also hired the son of a an employee who needed a job, even though there wasn’t quite enough work to keep another person busy. In the final analysis, revenue went up significantly, but costs skyrocketed. If you’re not careful, you’ll spend up all the profits.

9. Spreading marketing dollars too thin. The owner of a Tex-Mex restaurant in a part of the country that’s not exactly a hotbed of enthusiasm for Southwestern cuisine had an obvious need to advertise. And she did. She bought one cable TV ad, one radio spot and a small coupon in the local weekly. Although she spent plenty — several thousand dollars altogether — her efforts didn’t add up to a marketing campaign. Failure to spend wisely on an integrated and continuing marketing plan is an expensive mistake. In this case, her location is now a pizza parlor.

10. Underfunding an emergency account. When unannounced road resurfacing closed a popular dress shop’s doors for a month, it put the owner out of business because she had no emergency money and she couldn’t go a whole month with virtually no sales. As every gambler knows, no matter how good a player you are, you’re occasionally going to be dealt a bad hand. Likewise, every business needs a financial resource to turn to when disaster strikes. Bad things do happen frequently to good people and their businesses, so, like a good Boy Scout, you have to be prepared.

Jennie L. Phipps is a contributing editor based in Michigan.