I do
only with something small.......normally free rein to choose whatever they like from the sweet shop actually. and as I never normally let them have chewy sweets, they gravitate towards those!.
I am one of those tho that don;t judge a good report on how high their grades are, but more by what the teacher says about them IE, lovely child to teach/always comes in with a smile/friendly/puts effort into all they do, type comments. I feel that my child just being a pleasure is more somethig to rewards than how good they work, altho being bright is a bonus it is not my 'demand' so to speak.
I am happy that they treat others with respect