Sometimes I get tired of handing out stickers. I know the kids like something new, especially if it's something they can show off to the other students. Here are two other ways I reward children.
Using a Vis-a-Vis marker, I draw happy faces on the backs of their hands. (I use the Vis-a-Vis because it washes off with soap.) Sometimes I'll change up each face to give every student individuality, making some faces wink, stick out their tongue, have hair, wear a hat, have two front teeth, etc.
I've also invested in two lip balms - one in strawberry, and one in dulce de leche, or something the boys won't mind wearing (I'm out of chocolate, but it's quite popular.)
Each child who deserves the reward gets the back of one hand smeared with the balm.
Trust me, you'll catch them smelling their hands the rest of the day!