When filing a tax return a person has a choice between what is called a standard deduction or an itemized deduction, in 2018 that standard deduction has been set at the following rates:
Single Tax Payer - $12,000
Head of Household - $18,000
Married Filing Jointly - $24,000
Married Filing Sperately - $12,000

Alternatively, but only when it actually exceeds the standard deduction amounts, a tax payer can use an itemization of deductions. These deductions include such expenses as:

-Personal home mortgage interest and real estate taxes paid
-Personal state income taxes paid
-Charitable contributions made
-Certain Business Expenses paid
-Medical expenses paid
-Gambling losses (not above gambling winnings)
-Other misc. expenses