Emily L. answered 10/08/19
ESL, Chinese, Piano Teacher
Reading and memorizing, if you are solely aiming to expand your vocabulary bank. It takes time and effort to do so. I recommend using flashcards to study the words that you find from any resources, and you can also prepare a notebook specifically for this purpose! You can easily study from your flashcards when you are traveling on a bus, or eating lunch by yourself. This is the most efficient way to increase your vocabulary.
However, if you want to do more than that. I suggest you to read at least one article from newspaper everyday. As time goes on, you will know more vocabularies than you used to!