Large charitable donations

The IRS already is known to look closely at returns with a large charitable-donation deduction relative to reported income. For those who are "bunching" their donations, be aware that the move could get more interest than you intended.

Basically, the tax break for charitable contributions is one of the few deductions remaining. Yet to take it, you must itemize your deductions. And for that option to make financial sense, the total of all your deductions would need to exceed the standard deduction — which for the 2019 tax year is $24,400 for married couples and $12,200 for singles. 

So, facing a higher hurdle for itemizing, some taxpayers plan to "bunch" their charitable contributions. That is, you give two years' worth of charitable donations in one year (and nothing the next year) if it would mean being able to get the deduction.

However, the IRS knows how much taxpayers at various income levels typically donate. So if your charitable-contribution deduction is high relative to your income or in comparison to your income peers, look out.

"If you're bunching your contributions, that could spark interest," Shannonhouse said.

Of course, as long as you have the documentation to back up your donations, you shouldn't fear hearing from the IRS.

And remember the contribution limits: You can give cash donations of up to 60% of your adjusted gross income to qualified charities. Other types of donated property also face limits, depending on the type of asset and the organization it's given to.

Odds and ends

Along with making sure you get the nitty-gritty right — claiming all your income, taking advantage of any available tax breaks and ensuring you have the documentation to back it all up — it's wise to closely review the basics before signing and sending off your return.

"Double-check everything — Social Security numbers, your address, make sure all boxes are checked that need to be," said Shannonhouse, at the AICPA. "All those things help prevent your return from getting flagged at the IRS."