Be careful not to overstate your good deeds. The IRS has calculated the average donation level for each income range, so anything that far exceeds those amounts could cause the agency to take a second look at your return.

You're required to keep receipts for any donations exceeding $250, and to fill out Form 8283 for any non-cash donations exceeding $500.

Related: 12% of Americans say it's OK to cheat on taxes

And be realistic: non-cash donations are where a lot of people often exaggerate, so remember that the items you're giving to Goodwill should be valued at the price someone would actually pay for it -- not the amount you bought it for years ago.

"What you think it's worth probably isn't what the IRS thinks it's worth," said Pat Connolly, a tax partner at BlumShapiro.