Writing notebook entries is definitely one way to improve. When other members correct your errors, you will start to notice if most of your mistakes are due to punctuation, spelling, tenses or sentence structure errors. In addition, you will soon notice that some English words collocate (they are often used together). Using collocations make your writing appear more natural and sound more natural when it is being read.
I would say that reading should be done too. Read from a variety of sources such as the newspapers and reputable magazines such as National Geographic, Time and so on to examine their style of writing. Do not read passively. As you read, take note of their use of punctuation , writing style, vocabulary words and so on. Read with an active intent.
I always get my students to write their essays, edit and submit a second draft. Perhaps you can gather feedback from italki members, and rewrite on the same topic again, post it again and see if the number of corrections becomes fewer.
It certainly takes up more of your time, but you will reap the benefits.
Let the writing begin!