helper_example.py

from .layout import FormHelper, FormHelperMixin

class MyForm(FormHelperMixin, forms.ModelForm):
    
    class FormHelperMeta:
        # works like Meta, we just use to store property overrides
        # doesn't need to inherit
        # helper_class = MyCustomHelper
        submit_text = "Submit!"
        action = reverse('account:login')
    
    class Meta:
        model = MyModel
        
# layouts.py

class EmptyHelperMeta:
    pass

class FormHelperMixin(object):
    def __init__(self, *args, **kwargs):
        self.helper = self.get_form_helper()
        
    def get_form_helper(self):
       meta = getattr(self, 'FormHelperMeta', EmptyHelperMeta)
       helper_cls = getattr(meta, "form_helper", FormHelper)
       helper = helper_cls()
       helper.form_method = getattr(meta, "method", "POST")
       # etc etc
       return helper