In the case of W-2 employees, the deduction was eliminated in 2017 (it might be back in 2026, but no one knows for sure). You can still take the expense deduction in some states.
For self-employed, a home office deduction is allowed, subject to the rules in publication 587.
If you are NOT using the space for storage of inventory, then you must meet the regular and exclusive use rules.
You could dedicate 1/3 of your garage to exclusive use as a work space, but is it your regular work space? That's what might get you in the end. Where are you working, if not your garage? If you have a regular workspace someplace else, and use your home to store specialty tools that you don't need every day, or that you store at home for security, then your home is not your regular place of work, even if you use that portion of your garage exclusively for storage of work tools.
https://www.irs.gov/publications/p587
