1.Use meat/vegetable trays. Do not, for obvious reasons, use cutting tools. Meat trays are styrofoam, and therefore easy to cut into with a sharp pencil or a bamboo skewer. They also do not last forever but you get several prints out of each one.
2. Go slow. The first week, we made our blocks (this was a part of a radial symmetry lesson along with Islamic tile art) and did a test print in black ink. The second week, they were given colored ink to work with. The third week they combined colors on the brayers (alas, only one of my classes got to do a third week because Daisy got a fever on the third week for her class and we moved on to other things the following week).
3. Have other things for them to do if the class is large. Daisy's class is a 1st-3rd grade class of 31 students. They can't all print at the same time. So we had a station for children to color intricate snowflake designs and a station to create their own radial symmetry designs using pattern blocks. A fourth station (besides printing) was to color in previous prints from the week before.
4. Hover like a hawk the first week and make sure they know how to use a brayer. And then the second week, give them more freedom--let them measure out ink, for instance. The third week be a support person.
5. Constructive criticism regarding design elements, if done well, will make them happier with their results in the end. If their lines are too faint or too detailed, with meat trays, they will be disappointed. Bold designs.
7. Stress the idea that perfection is not the goal in printmaking--that the artist's hand is very visible in this medium. Inking errors are not necessarily errors. True errors (shifted plates for instance) can ben redone, but faded or bleeding colors, while not what the original goal may have been, are still beautiful art.