I think (with my experience) that it's to find a suitable teacher / native speaker who guide you time to time to improve your language skill
Hi Gustavo,
I had some difficulties to find a school that I like the material, the method and the teacher.
After that I had trouble to find time to study.
However, you have the most important job to do, you need to sit down and study. No one can to do it for you even if you have the best teacher, he is not a magician but just your tutor.
I think commitment is the most important thing you need.