Wrap a shoe box in white paper. Cover both the box and the lid.
Give the children a selection of stickers and allow them to take turns decorating the box.
Fill the box with a variety of small trinkets. These can be bought from a variety of stores online or from a dollar store. (See the Resources Section).
Keep the box in a location only accessible by you, the teacher. Take the box out when one of your students has earned a reward. This could be for a particularly nice act or for filling up a sticker chart.
Allow each student who has earned a reward to choose his own prize from the treasure box.