In a lot of my classes, we just have chatting time. We present a topic/question, give students one minute to discuss in pairs (and keep talking--they shouldn't just say the answer sentence and stop!), and then switch partners. After a few rotations, we give them a new question. I made this powerpoint for that kind of activity. It specifically has students practicing comparatives and superlatives. It can also be used as a simple warm-up to get students talking after they're pretty comfortable with the grammar.
The first question is about the most beautiful place in your area, so you should insert your prefecture or town's name and picture.
The question with the characters is about America, so feel free to change it to your country's name and answer.
If you need some speaking practice or a last-minute activity for comparatives and superlatives, this might be easy to use.