The potential for sweeping tax reforms this year casts a giant shadow over tax planning at the end of 2017. Despite the uncertainty, however, you can illuminate your current tax situation by following some basic principles. Consider these five tax aspects.

1. Itemized deductions/personal exemptions: With several major tax breaks on the chopping block—including most itemized deductions other than write-offs for charitable donations and mortgage interest—it makes sense to secure all of the personal tax breaks you can get in 2017. Grab what you can, but be wary of the Pease and PEP rules. Under the Pease rule, most itemized deductions are reduced by 3% of the amount above a specified level of adjusted gross income (AGI), but not by more than 80% overall. For 2017, the threshold is $261,500 of AGI for single filers and $313,800 for joint filers. Similarly, the tax benefit of personal exemptions may be affected by a special tax law provision. Under the personal exemption phase-out (PEP) rule, exemptions are reduced by 2% for each $2,500 (or portion thereof) of your AGI exceeding an annual threshold. The PEP thresholds are the same as those for the Pease rule.

Keep these two tax rules in mind when planning to claim itemized deductions and personal exemptions in 2017.