The following article was published by the IRS.
Changes from the Tax Cuts and Jobs Act mean the standard deduction is worth almost twice what it was before, so you may get more benefit from the standard deduction than from itemizing. To figure out whether you should itemize, you can search “how much is my standard deduction?” at IRS.gov or speak with a tax professional.
If you choose to itemize your deductions, the law change also affects what expenses you can claim on Schedule A. You may deduct medical and dental expenses that exceed a certain percent of your Adjusted Gross Income. The law now limits your total deduction for state and local, property, income, and sales tax to a combined total of $10,000, or $5000 if Married Filing Separately.
It also limits the amount of home mortgage interest and home equity loan interest you can deduct. Search Publication 936 at IRS.gov to learn more about these limits. You may usually deduct gifts to qualified charities too, and you may deduct personal casualty losses, but only if they relate to a federally declared disaster.
However, you may no longer take certain miscellaneous deductions as you have in the past, such as tax preparation, safe deposit box fees, uniform expenses, and union dues. Also, unreimbursed employee expenses such as meals, entertainment, and travel expenses are no longer deductible.
At any rate, add up all of these items to figure your total itemized deductions. Don’t itemize deductions unless your total is greater than your total deduction, or if you are required to itemize. For more information, visit IRS.gov and search “itemized deductions”.