Here are some ideas as well as some free printables:
Attach this to a bag or box of your favorite "Jolly Rancher" Candy :)
Attach this to your favorite Extreme Candy.
I gave the Jolly Ranchers to them before they left for school and then when they returned home I had some "Air Head Xtremes" for them and a note that I had hand written to each of them.
I also modified my YW Back to School handout, so it could be given by anyone, not just a YW leader :) Just tape or glue a package of "Extra" Gum into the box and some hugs and kisses chocolate candies into the circles :)