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)
Step 2: The Garden Bed
1) Cut off a strip about one inch wide; this will be for the rake. I creased the piece and then ripped it off. Set the strip aside.
2) Next, cut the paper in half once more, setting one half aside.
3) Fold the piece in half along the long side (hot dog style), then flip it over so the open side faces you.
4) Fold the two edges up about one centimeter, then flip it over again; keep the same edge facing you.
5) Now fold that edge again, a little more than the last fold. Now unfold the whole sheet.
6) Now, fold the the flaps toward the middle, on the second crease.
7) Fold the corners to the first line.
You will need to look at the pictures for the remaining steps. They are hard to explain via text.