Originally Posted by dixie_fried

Sorry you're having trouble! I am by no means qualified to tell you what to do. I can only tell you what I did and how it worked for me!
I had a little trouble getting my prints lined up. Once I gave up on having the selvedges straight, it worked better. The fabrics are not printed straight! I tore my fabric down the middle to start...the whole length. I identified a spot near the top of the fabric, nipped the length at the same spot all the way down and tore into 6 sections. Once it was stacked, I used a pin to line up a random spot that was easy to find from the edge of all 6 layers. The selvedges were NEVER straight once the prints were lined up.
Once I had the layers pinned, I decided how I could use the fabric best--for me, it was cutting 3.5" strips and then using my pyramid ruler to cut as many 3.5" triangles as would fit on each strip. Seam allowance were already added in thanks to my ruler!
When I sewed the triangles, I broke the rules, but what I did worked and I still have my hair. I took one triangle, laid the second on top of it RST, sewed the right hand side, set the seam. I opened the set of two, and pressed the seam allowance towards the left. Then I layered the third tri on top of this set and sewed, making sure the seam allowance from the first set got sewed flat on the bottom side of this seam. Set the seam, open and press the tri out with seam allowance to the right. The seams meet on the back and are crossed by an X of stitching and are forced flat. When the halves are joined the overlap isn't visible. I tried to press open the center seam and it didn't want to lie flat, so I alternated the row joins up and down and it looks fine that way.

I hope any of that makes sense. I will pull a half hex off the design wall and take a photo for you. Maybe that can better illustrate what i did since I'm pretty sure I didn't do it like you're supposed to...