Piecing together Django views
Your question is little too generic.
The general way of doing it involves:

Extend templates of the reusable apps
Pass the new template name to the view (Reusable apps should accepts that argument)
Also pass extra_context to the reusable-generic-view
Use your own view to create an extra_context and return the reuse-able view, from your view.
Is it good practice to treat individual app views as a blocks of HTML that can be pieced together to form a larger site? If not, what is the best way to reuse app views from project to project, assuming each one uses a different set of templates?