Add variables to layouts whereby users can enter values that do not need to be stored in fields. This would keep the relationship graph cleaner and cut down on needing to rely on global fields. Layout variables would look like a field on a layout.
A layout variable to filter portal records
Multiple layout variables on custom dialog layouts
Allows user to enter values into variables, then validate the values, and if they fail, variables can be cleared w/o data being affected. If values are validated, then Set Field script step could be used to commit values to database.