Itemized Deductions - Schedule A

MUST you itemize? If you are married and filing separately from your spouse, and one of you itemized deductions, the other must itemize as well or use a standard deduction of zero. This is the IRS's way of making sure you don't abuse the situation by having one spouse claim all the itemized deductions for the couple, while the other spouse claims a full standard deduction.
SHOULD you itemize? If your deductible personal and family expenses, as defined by the IRS, add up to more than the standard deduction for your filing status, and you have the records to prove them, you should itemize your deductions instead of claiming the standard deduction. To do that, you'll have to file Form 1040, and complete Schedule A and attach it to your tax return.
If you own your own home and pay interest on a mortgage, you likely will come out better by itemizing your deduction. Your personal expenses such as mortgage interest, property taxes, medical expenses, charitable gifts, and employment expenses can all count (within certain limits) as part of your Federal itemized deductions on Federal Form Schedule A to your Form 1040.
Preparing your Schedule A