Learners should be prepared to read in English every day and try to learn vocabulary from their reading. Learners should be prepared to read from a variety of texts e.g. magazines, websites, newspapers and novels.
There are lots of sites that introduce vocabulary daily or look at the meanings of words. How about suggesting that your student should visit a couple of sites daily?
You could ask your student to read this : Why are words so confusing? | IELTS ONLY
In my experience, there are no shortcuts!!
Hope this helps.