Normally to get a benefit from charitable donations you need to use Itemized Deductions on your US Tax Return. However, for 2020 and 2021 the CARES Act has a provision that allows for a deduction of up to $300 for Single, Head of Household or Married Filing Jointly taxpayers ($150 if Married Filing Separately) for 2020 or $600 for couples filing jointly in 2021 ($300 for other filing statuses). One caveat is that the donations must be in cash, so non-cash contributions (e.g. donations to Goodwill) do not count.
For expats, it is important to note that contributions to qualified US charities are considered “US Source” when calculating your foreign tax credit, which means that if you owe US tax in general, it is likely that you will see a tax benefit from this deduction, based on your marginal tax bracket. If you are in the highest tax bracket, then the deduction would result in a reduction of your US tax of 37% of the amount. Not a huge amount but also not a lot of effort to include this deduction if you have given to US charities during the year.