Can I deduct haircuts, manicures, makeup, socks, underwear, shaving cream, etc.?

No.  The reason is, these expenses are considered personal expenses.  The IRS will not allow personal expenses to be deducted.  This is a common source of disagreement from many crewmembers, but with these items, the IRS uses the logic that if an expense would be incurred even without the job, it is not deductible.  The IRS assumes that all of these expenses would be incurred, whether or not you were a pilot or a flight attendant.

The common argument among crewmembers is that their job manual states that they have to meet certain appearance standards.  Unfortunately the IRS doesn't buy into this argument, and therefore these appearance-related expenses are considered personal and are not deductible.