Well I will try this one more time. I know Susan is really up to her ears with the business so I will do what I can.
First make your pattern , keep it simple as detail will be added much later in the process.
Use either a copier and change the size to your desired size or scan it into a drawning program.
Step two Copy the simple pattern on to your board. Using carbon paper , graphite paper , newspaper , self made graphite paper.
Step three Determine the layers . Susan normally has a 7 layer pattern. The simplest releif carving have at least three layers .
Front ( foreground) Center ( middle ) and Back ( background)
Layout the layers from 1-7 and make each section . Here is a relief showing the steps
Relief Carving Wood Spirit Grape Man WIP
All relief are done in the same format .
Once you have established the layers determine the size of those layers. If they are 1/8 in depth then if your using 7 layers your carving will be at least 7/8 of an inch in depth. Which makes your block needed 1 3/4 inches thick.