We have learned it is best not to keep scores and award prizes for best quiz scores, as it highlights worst cognitive performance also. Instead we applaud significant contributions, such as someone performing a solo of a song they know and love, or getting up to exhibit a dance or other skill they have held in their long term memory. A beautiful freehand drawing or painting is held up as a thing of beauty. A bread dough mixed and rolled well is commented on as being something the whole group will later enjoy. For quieter or less able clients we comment on the brightest smile or the prettiest dress, or we add in a fact we know about them to the conversation which will make them feel we really respect and value them and give them a sense of pride in that especial lifetime achievement.
Of course, for non competitive games of chance such as Bingo or Jenga then prizes to hand out and share are a great treat for the whole group.