I bought steel toe boots for work how do I write them off

According to the IRS, you will only be allowed to deduct your work clothes/uniform if:

• the clothes are mandatory for your job and unsuitable for everyday wear (Determine which work clothes are necessary for your job but not suitable to wear outside of work. However, just buying clothes specifically for work and never wearing them at any other time isn't good enough. The IRS has accepted deductions for theatrical costumes, hard hats and other safety gear. Among the items that do not qualify are overalls, white dress shirts, and bibs even if required on the job site. For example, even though your company requires you to wear a suit each day, you cannot deduct their cost since you can wear the suits to weddings, job interviews and other occasions that don't relate to work)
• you itemize your deductions on your return (subject to 2% AGI limitation)

You would enter your uniform/work clothes in TurboTax (for TurboTax Online sign-in, click Here , then select "Take Me to My Return") under Federal Taxes>Deductions and Credits> I'll choose what I work on (or jump to full list)> scroll down to Employment Expenses> Job-related expenses (start/revisit/update). Use the TurboTax guide to help you enter these expense.  

• Enter your occupation information
• after about 6 to 10 question screens, you will get to a screen titled "Job-Related Expenses" you can put this information here (see screenshot)

Unless you have a lot of such expenses, don't bother. That is an unreimbursed employee business expense subject to a 2% of agi floor. What that means is that only the amount of such expenses that is more than 2% of your adjusted gross income is actually deductible. And You get no tax benefit from itemized deductions until all of them together add up to be more than your standard deduction.
2016 Standard Deduction
Taxpayer under 65, not claimed as a dependent
$6,300 for Single
$12,600 for Married Filing Jointly, or Qualifying Widow(er) with dependent child
$9,300 for Head of Household
$6,300 for Married Filing Separately
For over 65 or blind, add $1,250 for each instance or add
$1,550 each instance if single and not a surviving spouse.