Start with a manila envelope. You can use any size. Your final project will be larger if you use a larger envelope.
Fold it in half with the flap facing in and draw the shape you want on the cover. My example shows a tree.
Next, cut the shape out from the top part of the envelope. You will have two layers.
At this point you can either leave both pages the same shape or you cut the bottom one into a different shape. In my example, I cut the bottom into a tree more resembling a deciduous tree, like a maple.
Then you can add more information. Post it notes, specimens, labels.
Packing tape seals the specimens down neatly so that they do not mold.
The pocket can be used for extra information, pictures from magazines, writing, stories, or diagrams.
The back is another space for information.
The subject matter of this shape book was trees. I compared two types of trees: coniferous and deciduous. Of course you could use this method for any subject. If you leave the back free of information, you can adhere it to your science notebook and make and interesting pop-out of information.
For more information and ideas see http://www.teacherspayteachers.com/Product/Shape-Book-From-Manila-Envelope-879584