Insurance on investment property. Also, home office is a MUST. Be careful of deducting closing costs. Can't expense them. You have to add them to the cost of your rental and then depreciate. If accountant said you could, you may want to find another accountant, or at least ask another one.
Some of your deductions will depend upon whether you have formed a company or not. You can employ your spouse and buy them health insurance,you can purchase your vehicle by your company and depreciate it and repair maintain it., etc. Anyway just some ideas for when the taxes start biting you because the profits are higher than normal depreciation.