Most Native American designs are geometrical, unless you get into the Woodland tribal designs, which are floral and intricate patterns.
I took art design, so the geometrical is easy for me -- ruler and pencil is about all I have to depend on. The tribal colors are only two or three colors.
That is why I thought the Assisi method would work well with Native American design.
I also like to go through old embroidery design books and pick up antique designs. If I can trace it, I can embroider it.