In this chapter, we will cover the following topics:
- Using model mixins
 - Creating a model mixin with URL-related methods
 - Creating a model mixin to handle creation and modification dates
 - Creating a model mixin to take care of meta tags
 - Creating a model mixin to handle generic relations
 - Handling multilingual fields
 - Enabling schema microdata enhancements
 - Using migrations
 - Switching from South migrations to Django migrations
 - Changing a foreign key to the many-to-many field