Enter "union dues" in the search topics box.  Job related expenses must be reduced by 2% of AGI before the remainder becomes an itemized deduction.

Medical expenses must be reduced by 10% (7.5% if over age 65) of your AGI before they become an itemized deduction.

Miscellaneous deductions, such as union dues, job related expenses, etc., must be reduced by 2% of AGI before they become an itemized deduction.

Unless all itemized deductions exceed the standard deduction then there is no benefit to itemizing.

Most taxpayers cannot itemize unless they have some very large deductions (such as mortgage interest and property tax) to overcome the standard deduction.

Itemized deductions will only be of benefit if all itemized deductions exceed the standard deduction.

For 2016 the standard deductions are:

Single or filing Married Filing Separately - $6,300
Married Filing Jointly or Qualifying Widow(er) - $12,600
Head of Household - $9,300

(If over 65 or blind add $1,250 - $1,550 if filing single or HOH)