For a 2 page layout, I use the 12x24 mat and add each item and its shadow like I want it on the paper. I make sure each item is grouped with its shadow. Here is the completed layout on the gypsy screen.
I then move everything to the right side of the screen so that it is only on one 12x12 mat. Make sure you move the items grouped.
I change the mat size to 12x12 and copy/paste each image on several pages. This particular layout ended up being 5 pages.
Here is everything bunched togeter on the 12x12 mat.
Here are the 5 pages after I copied/paste on seperate pages for cutting.
I love doing my layouts and cards this way. It is so easy and it allows me to tweak my projects to make them just right.