my 2 cents from someone who used duolingo quite a bit but not intensively:
* add grammaticals notes, preferably attached to grammatical "objects" and not separate lessons. They may be boring but invaluable to understand a language
* explore other ways of teaching (for example the model of lingua latina per se illustrata)
* try to see if you can improve on the speaking exercices
*
my 2 cents from someone who used duolingo quite a bit but not intensively:
* add grammaticals notes, preferably attached to grammatical "objects" and not separate lessons. They may be boring but invaluable to understand a language
* explore other ways of teaching (for example the model of lingua latina per se illustrata)
* try to see if you can improve on the speaking exercices *