More and more business people are working for themselves. Be your own boss, have more flexibility, and enjoy what you do – who wouldn't want to be an entrepreneur? In the constant battle to keep the bottom line high, sticking to a budget can be one of the biggest challenges faced by entrepreneurs. Even the smallest things, such as post office expenses and bank fees, can add up if not dealt with carefully. Below are five expenses that entrepreneurs find take the biggest bite out of their budget.

1. Insurance

With healthcare costs rising an average of 18% each year nationally, entrepreneurs are taking a long, hard look at what they can do to keep costs down. Like anything else, shopping around is probably the best way to find competitive insurance rates. At the end of each insurance policy period, review your business's needs and get several bids before renewing your policy. Check with your local trade association, which may surprise you with competitive group insurance rates. You can also raise the deductible on your insurance and your employees' insurance, which will lower your premiums. Finally, consider having your employees pay for a portion of their health care, another premium-buster.

Many entrepreneurs also tend to overpay their rental insurance. When their employees rent a car, many entrepreneurs insist they purchase liability and collision coverage. Most general corporate insurance policies contain a stipulation for rental car coverage. Check with your insurance broker. If this condition is already covered, you can avoid paying for the same thing twice.

2. Taxes

As more and more entrepreneurs do their own taxes, many are overpaying by hundreds of thousands of dollars. Even entrepreneurs running a very small business will have a hard time figuring every credit, deduction, real estate issue, and tax due without hiring an expert.

Taxes are overpaid in other ways too. Entrepreneurs habitually over-estimate quarterly tax payments because the IRS charges significant penalties for an underestimate. Home-based entrepreneurs can deduct part of the cost of their home, equipment, utilities, and more, but it is very difficult to determine those deductions.

The best bet is to spend the extra funds on hiring a professional bookkeeper and/or accountant. What you spend on this professional will more than likely be earned back with what you save on taxes.

3. Employees

Overpaying employees is a common mistake made by entrepreneurs. They believe that you get what you pay for, so if you pay more you should get more, right? Not always. However, there are ways to entice quality employees without overpaying them. Attractive benefits, vacation time, and flexibility can draw a bright, highly-skilled staff. In addition, if there are times when business is slow, it may be cheaper to hire temporary employees rather than a higher-paid full time staff. Or, you can cross-train employees to handle more than one job, so that you do not need additional help.

To figure out if your employees are overpaid or underpaid, research recent surveys containing pay data for your line of business and location. These can be found through local colleges, human resource groups, chambers of commerce, and on the Internet.

4. Advertising

Advertising can be an expensive but necessary expense for running a successful business. Many entrepreneurs, especially those just starting a business, unknowingly overpay for advertising. There are many ways to combat an ever-increasing advertising budget and still get your name out to the public. Before spending any money on advertising, prepare a marketing plan. The plan will outline what advertising is needed for your business and summarize how and where you can cut costs, if necessary, while still hitting your positive results.

Otherwise, there are lots of ways to cut advertising corners. Like to procrastinate? Many magazines, television and radio offer last-minute, unsold ad space at a discounted rate. You can also advertise on forms you already have, like invoices or newsletters, which will help save on advertising postage and other expenses. If you know your neighboring businesses, investigate splitting advertising costs by jointly promoting your goods and services.

5. Themselves

When you're finally paying yourself, why not pay yourself as much as possible? Entrepreneurs sometimes overpay themselves, either through fringe benefits, perks or an inflated salary. Many times this is done by showing lower profits for their business, but this is a risky move that can backfire. Not only may an entrepreneur who overpays him or herself decrease the value of the company without even knowing it, the company may become less competitive in the market than its more profitable competitors.

Better Money Management Starts at the Top

There are external resources that entrepreneurs can use to better manage their budget. Trade associations are an excellent resource because they can give you specific information about your particular market niche. In addition, many trade and business associations offer discounts on health insurance, phone and credit card services, and car rentals, all for reasonable membership fees.