Pyramage is very similar to decoupage and the method is exactly the same. You need exactly the same tools (although a proper paper trimmer helps) and you will get a very similar result of a layered final image but as the name suggests, the finished style will be that of a pyramid.
The first picture, below, is the example I used to show decoupage in my previous lesson
In pyramage, the shape of the image is not really important- a basic shape e.g. square, circle, triangle or rectangle is used instead (as shown below)
Pyramage can be easier or harder than decoupage depending on the image used but I feel it is easier to create your own design as I did here starting from just 4 exactly the same images (printed from the Papermania 'Enchanted' cd-rom). You do have to be careful that when you cut the layers, take an even amount from each side though, otherwise the balance of the design will be off.