I spend an hour or so reviewing the notes I made last year when studying HSK level 2 grammar on Chinese Grammar Wiki. (If you are learning Chinese, I highly recommend this site.) I had forgotten some of the grammar points so it was good to refresh my memory.
I listened to the audio from a vocabulary book published in Japan. It has all the vocabulary needed from HSK 1 – 4. I listen to this in my car when I’m out and about. I am starting to pick out more and more sentences, which is good.
This is the book. It’s called “HSK grades 1-4 word training book” and is aimed at Japanese speakers who are learning Chinese.