You see, I found my self in a situation like yours not too long ago. I was sitting in algebra, there was still thirty minutes left. How am I going to make it? Well I did, barely. So I decided that would be the last time I would be without a solution. Thus, the paper zen garden was born.
Step 1: Materials
fine dirt or sand
construction paper/colored paper (instead of plain paper)
scissors (in order to make neater cuts)