Donating items to charity is a great way to find a new home for your old things, get a tax deduction and help a nonprofit raise funds. But not everything can be donated to charities, so it's best to ask before you drop off. Mattresses and box springs, for example, are difficult to give, since it is illegal in most states to refurbish or resell beds. Used electronics have become difficult to donate since prices have come down and functionality is constantly evolving. It's best to bring old electronics to stores like Best Buy to have them recycled.