Most people who give to charity in retirement are doing it in the most expensive way available, and they have no idea.
They take money out of the IRA. They pay income tax on it. Then they write a check to the church or the food bank, and because they take the standard deduction like almost everyone does, they get no tax benefit for the gift at all.
Taxed on the way out, no deduction on the way in. The government takes a cut of a gift you never kept.
There is a route that skips the tax entirely, and it has been in the code for years. It is called a qualified charitable distribution, and for anyone over 70 and a half who gives to charity, it is almost always the correct move.