you ca do it straight on to the tear away, you would do a die line for the fabric, lay the fabric down, do the next, I would do the first decorative stitch at that time, then add the next die line and the next fabric. there are a few things that you can do to get a good lookin block, though you would want more than one block, you need to be familiar with your software though to do it,
I have not done this kind of block but I have been digitizing for about 15 years.