SALEM, Ore. (CNN/Money) - The difference between owing taxes and looking forward to a refund check often comes down to one word -- deductions.

You can always claim the standard deduction -- $4,850 for single filers and $9,700 for married couples filing jointly -- and it is often the best bet for people with simple tax situations.

But depending on your mortgage interest, charitable gifts, state taxes and business expenses, your actual deductions could be several times the standard deduction, in which case you're missing out if you don't itemize. A single filer in the 25 percent tax bracket with $8,000 in deductions would save $787 by itemizing her deductions.

To help your search for deductible dollars, here is a list of claims often overlooked.

Medical and dental expenses: Most people don't get a medical deduction, said Martin Nissenbaum, national director of personal income tax planning for Ernst & Young, because your medical expenses need to exceed 7.5 percent of income before you can deduct them. That is, if your income is $100,000 and you have $10,000 in eligible expenses, you will be able to deduct expenses above and beyond $7,500. That's a high hurdle, but remember that premiums for long-term health care insurance, mileage to and from appointments, over-the-counter medication and a laundry list of other expenses may be deductible, said Nissenbaum.

Sales tax and personal property tax: In 2004 and 2005 you have the option of deducting your state sales tax or your state income tax. Which deduction should you take? That's an easy one if you live in a state with no income tax or sales tax. If your state levies both, compare you state and local income tax with the IRS sales tax table for your state, making sure you account for local sales tax and big-ticket purchases. While you're at it, be sure to deduct any personal property tax you paid on a car, boat or airplane.

Charitable donations: If you're generous but not organized, you might forget to deduct all that you've given to charitable organizations, particularly if you've given cash gifts or "in-kind" donations of clothing or appliances, which you can deduct at fair-market value (i.e. what your local Salvation Army or Goodwill will get for the item.)

If you didn't keep all your receipts, you can go through your check register, look through your old credit card statements or give a detailed explanation of the donation, including date and amount, said Kathy Burlison, a tax pro with H&R Block. Remember that your donation must be made to qualified organizations, not individuals. And while you might think your time is money, any time you volunteered for a cause is not deductible. Click here for the IRS info on charitable contributions.

Education expenses: Looking at the IRS's 83-page explanation of educated-related tax benefits, you can see why education expenses and savings may be easily overlooked at tax time. There are educated-related deductions and credits for nearly every stage, whether you're using a 529 to save for your two-year-old daughter's Harvard education, struggling to make tuition payments today or still paying off your own college degree.

Disaster or theft: "There have been a number of natural disasters recently that could result in casualty loss deductions," said Nissenbaum. If your home or other property is damaged by flood, ice storms, earthquakes, other disasters or theft, you may be able to deduct what your insurance doesn't cover. One caveat is that each loss must be at least $100 and your total losses for the year need to be at least 10 percent of your adjusted gross income before you can claim the deduction. Click here for IRS publication.

Miscellaneous expenses: True to its name, this category includes everything from business expenses to gambling losses. In this case your total miscellaneous expenses must exceed 2 percent of your adjusted gross income before you can start tally these deductions, said Burlison. "If you think you might be close, go back and check your calendar," she said.

Among miscellaneous deductions are:

• Job search expenses: If you were in the market for a new job in 2004, you can deduct most expenses related to the search, including cost of resumes, phone expenses, postage, career counseling and travel to and from your interviews, said Mark Luscombe, principal analyst for CCH Incorporated. "People are so focused on the job hunt they forget to keep track of their expenses," he said. As with all deductions, there are caveats. Expenses related to changing fields may not be deductible. Interview garb is definitely not deductible, said Nissenbaum."Clothing is never deductible unless it is a uniform."
• Investment expenses: This includes everything from brokerage fees to safety deposit boxes to subscriptions to investment publications, said Luscombe.
• Gambling losses: If you won big in Vegas you'll have to pay taxes on your winnings, but you can offset some of your gains with gambling losses. "People don't realize that if they win they can actually take a deduction for expenses they incurred or if they had losses," said Nissenbaum.
• Tax return preparation: There might be a double benefit of hiring an accountant or using tax software to file your return. Not only might you remember to claim deductions you might have otherwise deduct, the cost of filing your taxes is yet another expense deductible under miscellaneous expenses.