I'll confess: I filed my tax return on April 15. This year, the time just seemed to come up so fast.

But my husband and I have already talked to our tax preparer about our 2008 tax situation. You see, this is the time to begin looking at your taxes for next year. If you start now, you can make some changes throughout the year to help you save on your bill or at least put aside the right amount should you end up owing money.

I'm talking to the folks — particularly small-business owners, freelancers or the self-employed — who fall into two categories.

The first are people who didn't withhold enough money during the year and got hit with an underpayment tax penalty.

Our tax system is pay-as-you-go, which means the government expects you to pay your taxes as you earn your income. You can comply by having money withheld from your paycheck. If you don't do that, then you have to make estimated tax payments. If you do not pay enough tax, you may have to pay an underpayment penalty. Last year, about 7.7 million people were hit with a penalty for underpaying their taxes.

To avoid the penalty, you have to pay at least 90 percent of the tax for the current year, or 100 percent of the tax shown on your return for the prior year, whichever is smaller, according to the IRS.

The second group is people who had to scramble to borrow money to pay their taxes — sometimes on a credit card — or had to request an installment agreement with the IRS. If you are self-employed and you found yourself in this position with your 2007 return, make a promise to change the way you handle your money this year.

I know, times are tight. But bad budgeting can be costly. In 2007, nearly 3 million installment requests were accepted by the IRS. Even though the IRS allows you to pay what you owe over time, penalties and interest will continue to be charged on the unpaid portion of the debt.

Let's say that as money comes in, you use it to pay your personal expenses. You intend to use further earnings you receive later in the year to cover any tax obligation.

But what if your business slows down? What if you lose a major client? You can't always count on future revenue, particularly in this economy. The wiser move is to immediately set aside the money for taxes when you receive your income.

Another tax planning tip for next year's return: Stop getting large refunds as a forced savings plan. If again this year you are still getting a large refund absent a major change in your tax situation (got married, had a kid, bought a home), you probably need to increase the number of withholding allowances on your W-4 form.