Adjust your withholding so that you don't have more deducted from your paycheck than is required (or if you're self-employed, rework the numbers to make sure your estimated quarterly tax payment is correct). Online tools can help you calculate the exact amount; just type "withholding calculator" into a search engine. Try to estimate carefully, and remember that it's okay to owe the IRS a small amount at the end of the year.
Those of you who use the standard deduction when filing tax returns should consider itemizing. A few years ago, the Government Accountability Office found that 2.2 million people who took the standard deduction could have reduced their tax bills by an average of $438 if they had itemized. TurboTax or TaxCut software can do the calculations and determine whether it makes sense to itemize.