The lower level is to be able to read novels, newspapers without much difficulty. Even when there are quite a few sophisticated words, any college graduates usually have no problem to read and understand. However, if you ask the reader to repeat or re-write the piece of content, they found it hard or time-consuming to do so on their own.
The higher level – relative to the lower level – is to be able to write fluently and smoothly.
Clearly, the former one is passive, the latter is active.
We should elevate ourselves to the higher level. rather than satisfied being a passive information taker.
To improve and reach the level two – a mastery higher level language users, I think the key is on twofold: a enormous vocabulary and different ways of structuring words.
For the purpose of enlarging vocabulary, an effective way is to constantly connect words by finding their synonyms and antonyms. Taking note and refresh them periodically following Aibinhos memory rule.
To get better at orchestrating bricks/words together in a fluent, smooth structure, yet grammatically correct, I think the effective approach should be: find the best writer, columnist and deliberately re-write and compare why her/his version exceeds yours.