I work for a group of international colleges (teaching foreign students English), and one of our English teachers at our London colleges has been writing a series of blogs about slang, idioms and suchlike. I've been creating illustrations for these articles, a portrait 'thumbnail' with explanatory words, and a main landscape image without the words to display on the article page. It's been fun.
Compliments and insults
Words for when you can't think of the word (yet to be published)
Weather related idioms
They've also been doing a 'word of the week' feature on the Facebook page, where various members of staff pick their favourite word and I illustrate it.
Here are a few!
I picked bottom. Obvs.