At the intermediate level, you can understand Japanese to some extent, so you can take it easy if you want to. However, in order to move up to the advanced level, more effort is required. Specifically, it is important to make efforts to improve your “accuracy” and “fluency.

I will explain them in detail in this order.

(1) Improving accuracy
Some people repeat wrong usage over and over again. In technical terms, this is called “fossilization of misuse”. It is a condition in which a language item or rule has been learned incorrectly and remains as such. It is most likely that you are not aware of the error, or you disregard the error, but to a native speaker, the error may be worrisome. Ask a native speaker or a Japanese language teacher to point them out and correct them.

(2) Improve fluency
You need to learn how to say and use things in a more native-like manner. The most effective ways to do this are to read more and shadow-wing. Expose yourself to what native speakers read and listen to as much as possible.

Social Media