I am always trying to think of fun ways to get students excited about vocabulary! This is a great tool you can set up in your room. All you need is a jar labeled "Word Jar" and these slips. As students find new, interesting words in a text of your choosing or their own, they fill out a slip and add this to the jar. Each week, I choose 5 words to go on a section of our word wall. The students who added the words I chose get to explain their word, where they got it from, and why it is interesting/useful.
I find that the best way to teach vocabulary is to incorporate numerous smaller activities such as this into your lessons. Good luck! Let me know if you have questions!