I’m coming around to considering Django-seal to be mandatory for non-trivial applications. It will “seal” a query set so that you can’t make accidental DB lookups after the initial fetch. That way you can be more confident that you are doing the right joins in the initial query, and you are safe from the dreaded O(N) ORM issue.

SqlAlchemy has this as part of the ORM, it should really be part of Django IMO.