I recently switched from Django 1.6 to 1.7, and I began using migrations (I never used South).
Before 1.7, I used to load initial data with a fixture/initial_d
The solutions presented above didn't work for me unfortunately. I found that every time I change my models I have to update my fixtures. Ideally I would instead write data migrations to modify created data and fixture-loaded data similarly.
To facilitate this I wrote a quick function which will look in the fixtures directory of the current app and load a fixture. Put this function into a migration in the point of the model history that matches the fields in the migration.