Confession time: reviewing vocabulary with students is not my strongest point. This isn't necessarily a problem, since many higher level classes don't need so much help: I've tended to advise students on how they can research a word online to learn pronunciation, definitions, collocations, related words and example sentences then largely leave them to it. (1)
But there are students who don't yet have these independent study skills, and generally also for lower levels much more scaffolding will be needed.
So here's a roundup of ideas and activities for reviewing vocabulary from around the web, and a few thoughts of my own.