Beginning in 2016, the Safe Harbor Election allows you to expense business assets costing $2500 or less that would normally be subject to depreciation.
To expense the cost of business assets purchased for $2500 or less, first go to the Assets/Depreciation section for your business (self-employed, farm, or rental) and answer the questions to make the Safe Harbor Election.
Then go to the Expenses section and add these items under the most appropriate category. If in doubt, you may report these costs as "Other Expenses" (usually the final screen in the Expenses section) using your own description.
If you're reporting a business on Schedule C, go to the Business tab, then Business Expenses, Other Common Business Expenses. To enter your own description, use "Other Miscellaneous Expenses." The entry screen provides several boxes for descriptions and amounts.