The new federal tax law takes effect for tax year 2018. One of the biggest changes is a near doubling of the standard deduction to $12,000 on single returns, $18,000 for head-of-household filers and $24,000 on joint returns. That’s up from $6,350, $9,350 and $12,700 in 2017. Individuals age 65 or older and blind people …