I suggest you try 3 things:
1) Drills: drill the students briefly. Keep it light, short and get a good rhythm going. You can do this for a few minutes and then remember to correct (or invite students to correct) any mistakes that come up afterwards.
2) Take a list of adjectives; students pick one and describe the last time they felt happy, sad, angry, etc. Ask them to say what happened.
3) Ask them to choose a famous person from history (someone who isn't alive). Ask them to describe the main events in the life of that person.