I have an app where there are some search forms on different pages. One commonly used form field would be ‘show x items’, where x can be 10, 20 or 50. I would also like a field ‘Sort by’ with some standard values. I have used Django model mixins earlier, e.g. CreateTimestampMixin, which standardizes the column name ‘create_ts’ in my models, and I want to have something similar in my forms now. Note: These are just forms, not model forms. Is there a way that I can do it? Or must I only define a new field type that derives from forms.ChoiceField, plugin my choice values, and then in each form define this field?