Per yardage requirements, you need at least a dark, light and medium of each color. When I first started making the blocks I wasn't "daring." I stuck strictly to the diagrams pattern. I'm glad I didn't go in order, because the more blocks I did, the more I changed it up. (I started with the gem colors I liked the most. lol)
I used the 10" stack Color Wheel Solids Complete Stack from Connecting Threads, so I had a lot of tone variations. I printed a picture of the actual gem and noticed it went from light to dark. The lightest color was almost a peach and the darkest was almost brown. I decided to add this into my block in small bits, but keeping the primary color Red-Orange. I was really happy with the outcome, it brought more interest to the block (especially one I wasn't crazy about.)
I ended up with a total of five fabrics. I wasn't sure how I could go about adding these extras. This isn't like patchwork where you have the same little square and can swap it around. So I got out my markers and decided what color would represent which fabric. Looking at the gem picture, I started filling in the areas I wanted to be each color. I wasn't happy with a few placements, so I turned the piece over and colored in the back. I ended up with a few colors touching each other, but I was okay with that. Next was cutting and basting. I have a video posted in the Facebook group "The Quilted Diary Sew Along" that shows several different basting techniques. The actual construction instructions are pretty detailed, so I won't get into those here, but if you have questions just ask.
Always starch your fabrics before cutting for English Paper Piecing (EPP). There are a couple specific reasons this is important. First, even though you may have purchased reputable, high quality fabric, it may not really be square. This use to be square came from a 10" stack (AKA "Layer Cake") and it is a high quality fabric. As soon as the starch hit it, the fabric shrunk up into this wonky square. You do not want your fabric going back to it's natural weave after you have cut it out. Secondly, for EPP your fabric needs to have a little stiffness so the weave doesn't become misshapen while sewing.
If you have any questions, Facebook is the place you can reach me the fastest! Please share your progress this week and of course final pictures! Here is my finished Sardius block.