####
#### Django 1.6 (old)
####

class ManagerClass(PassThroughManager):
    class QuerySetClass(QuerySet):
        def queryset_method(self):
            pass

    def __init__(self):
        # voodoo
        super(ManagerClass, self).__init__(queryset_cls=ManagerClass.QuerySetClass)

    def manager_method(self):
        pass

class ModelClass(BaseModel):
        …
    objects = ManagerClass()


####
#### Django >= 1.7 (new)
####

Three options!

# 1 // Using queryset as manager

class QuerySetClass(models.QuerySet):
    def method(self):
        # do a thing

class ModelClass(BaseModel):
    ...
    objects = QuerySetClass.as_manager()

# 2 // Using Manager by itself

class ManagerClass(models.Manager):
    def method(self):
        # do a thing

class ModelClass(BaseModel):
    ...
    objects = ManagerClass()

# 3 // When you need custom methods on both queryset and manager

class ManagerClass(models.Manager):
    def method(self):
        # do a thing


class QuerySetClass(models.QuerySet):
    def method(self):
        # do a thing


class ModelClass(BaseModel):
    ...
    objects = ManagerClass.from_queryset(QuerySetClass)()