I like to create a Financial Attribute & Lookup in "Other Work" in Classic.
First, you must define the list of values that will appear in the dropdown.
Navigate to Classic UI > Administration > Studio > Lookups.
Click New.
Choose the Source:
Static List: For a fixed list of values (e.g., "Category A", "Category B").
Dynamic Query: For values pulled from a database table via NSQL (e.g., pulling a list of active Users).
Enter a Name and a unique Lookup ID.
Click Save.
If you chose Static, go to the Values tab and click New to add your dropdown options.
Now, link that lookup to a new field on the Other Work object.
Navigate to Classic UI > Administration > Studio > Objects.
Search for and click on the Other Work object.
Go to the Attributes tab and click New.
Fill in the details:
Attribute Name: e.g., "Work Category"
Attribute ID: e.g., ow_category
Data Type: Select Lookup.
Lookup: Click the binoculars icon and select the lookup you created in Step 1.
API Attribute ID: Provide a name (e.g., owCategory) so it appears in the Modern UX.
Click Save.