BOM Settings Dialog
In the BOM Settings dialog you can set the default values for the BOM Type and BOM Options for the Grid,
and for the export options to Excel.
File and CustomData Properties
You can also always and automatically assign additional properties to all files you open in: Default File Properties and/or Default CustomData Properties.
In CustomData, you can choose to assign them to assemblies only, parts only, or both; and the field name will be set automatically to the assembly or part see here for more options.