As you are building your vocabulary, I suggest that you search particular words or phrases from your vocabulary list on Twitter Search https://twitter.com/search-home?lang=ja , making sure to put phrases “in quotes.” (You have to be quite creative with searching phrases because grammar and word order can be so varied.)
Vocabulary searches very often lead to a seemingly endless array of tweets in everyday language from which to take your pick and should also expose you to more slang and common abbreviations. It’s a good way of finding a wider sample of how a particular word or phrase is being used in everyday speech, since most people tweet the way they talk. It’s usually pretty easy to separate out the careful or articulate writers from the sloppy or not so articulate.
This will invariably lead to more vocabulary. Try it out and let me know what you think!
You might also try crossword puzzles as a way of challenging your vocabulary as well.