Incorrect account and routing numbers: It’s convenient to have your tax refunds deposited directly into your account, but make a mistake in citing the account number and your return may end up in someone else’s account. At the very least, the error will cause your refund to be delayed. Check that number once, twice, and thrice.
Forgotten tax deductions: Did you donate your car to a car donation charity such as Kars4Kids? Don’t forget to claim the deduction. You have it coming to you, after all.