Deductions & credits

Thank you, I'm still confused on how to deduct the asset. When entering the asset I'm given options on how to expense/depreciate.  Say the phone cost $800 and I used it 50% for business & 50% personal. Which option should I take?  The options given are spread the deduction over several years, deduct the full value this year, take a partial section 179 this year, take a partial section 179 deduction this year & the 100% special depreciation allowance, or the 100% special depreciation allowance.  Thank you...