If you don't have a Flocabulary subscription, you can always rely on Schoolhouse Rock to provide a fun sing-along.
As we transitioned to using conjunctions specifically for writing compound sentences, we began using this pocket-chart exercise as a center activity. I found this activity in the April/May 2013 issue of The Mailbox, and it has been a great addition to our center rotations this week. As you can see in the image below, I displayed five sentence starters, each followed by a different conjunction. To complete the activity, the student can put any of the conjunctions provided at the end of each sentence starter. Then, he/she writes each sentence starter along with the conjunction and completes the sentence to create a new compound sentence. If they finish the activity with time to spare, they can scramble the conjunctions and write different compound sentences. It's also a good idea to provide highlighters which students can use to highlight their commas before the conjunctions as they write (highlighters make every activity fun for my students).