Ask them to work in groups to make a list of 10 things they could do with a lunchbox apart from carrying lunch (Lots of suggesting, ranking, agreeing and disagreeing language). Then gradually merge groups to integrate and re-evaluate ideas to end up with a whole-class, student generated “10 things to do with a lunchbox (apart from carrying your lunch)” :)
You could also get them to make ‘kits’ depending on topic (First aid, desert survival, moon trip, Jungle trip etc) following the same kind of procedure.