First off: a big shout-out to Rosa R., who showed on her blog how she pieced the diamonds and the background. (Smacking forehead) Why didn't I think of that? Now I can do G-11 and similar blocks, like J-1 Josepha's Jonquil etc.
For this, I use the EQ software to print out the block outline on paper-piecing paper. Then, I add pencil lines to the diamond shapes to make a piece-able sub-block. And number the pieces too to keep me on track. Sorry, forgot to take a pic of this step. I'll try to remember this when I do J-1.