At school we are going to make stain glass Valentines hearts. You can do it two ways. A. You'll need wax paper, glue and tissue paper You lay out the wax paper and spread glue on it. Then you put the tissue paper on. Put another sheet of wax paper on and you're done.
B. You'll need tissue paper and contact paper. You lay out the contact paper and stick tissue paper to it. The put another sheet of contact paper on top.
Once you're done with either way you cut out a heart and punch a hole in the top of the heart string in a ribbon and hang it in the window. You could add ribbon to the edge if you want to fancy it up.