The certificate just needs child's name and teacher's name inserting at the bottom. The behaviour jigsaws are something I find works well - talk with the child first about something they like, such as dinosaurs here. Explain their targets, type them into a text box with the child present. Put their name at the top. Then, laminate and cut into a set number of pieces. The child earns one piece every time they exhibit the good behaviour and this can be as subtle or as obvious as you want your behaviour scheme to be.