No occupation is considered a job related expense deduction. Some occupations are more likely to have expenses than others. bar tending is not normally one of them. Job and/or business related expenses must be both "ordinary and necessary" to be tax deductible.
Starting in 2018, employees (W-2 recipients) are no longer able to deduct any job expenses. Even in the "old days" you only got to deduct that portion of your misc. itemized deductions deductions that exceeded 2% of your AGI, and then only if your total itemized deductions exceeded the standard deduction (which was doubled under the 2018 tax law. . (2% rule explained: https://ttlc.intuit.com/questions/2902781-what-is-the-2-rule ).
If you are a self employed individual or contract employee, you are allowed "business" (job related) expenses deductions. The IRS considers anything in box 7 of 1099-MISC to be self employment income.
The IRS also considers undocumented cash income (no W-2 or 1099-MISC), for work performed, to be self employment income. Enter at "Business Income & Expenses" and TurboTax (TT) will complete Schedule C for you and allow you to deduct any expenses associated with this income. You'll also have to pay self employment tax (social security & medicare tax) on any profits greater than $400. You report the income from your own records.
