I have spent some time studying Django and I've done some applications. But I really don't know what is the best approach while developing an application, I mean, there are several options: Make all the models, then all the urls, the views and then make all the templates. Other people recommend using an agile approach, take a use case and go all the way until it's totally functional, and of course there might be other possible recommendations. Personally I feel really attracted by the agile approach, but I don't really know because for example every single model I append to my database would imply to create a new one.
To sum up, what is the best approach one should take when developing and application in Django, taking into account all the consequences that it carries?