Here's some suggestions to add to Margo's tutorial for those that want to use slightly oversized pieces. I've done it both ways but found my students prefer the larger pieces.
Make your templates adding 3/8" seam allowance. Then if you are using an Add-A-Quarter ruler to cut the pieces, cut 1/4" off one side of the templates.
Attachment {!-- ia2 -->QS124.jpg{!-- ia2 --> not found
The size strips you will need are 3" x width of fabric (42"). 11 strips of each fabric should be sufficient. Each strip should yield 23 units plus 2 half units. If I added correctly you will need 208 blue units, 64 blue half units (cut 32 as mirror images), and 240 orange units. Since you have 36" of fabric to work with you should have plenty of fabric for this method.
I put some double stick tape on the back of the templates. When cutting every other unit you will need to either flip the fabric over or flip the template over. Since I didn't want to take the time to put double stick tape on both sides of the template I flipped the fabric over. (As an after thought it doesn't matter which way the full size template goes. It will still be the same size. The half size will make a difference though to get the mirror images). Layer at least 4 strips for faster cutting.
Attachment {!-- ia1 -->QS125.jpg{!-- ia1 --> not found
I added guidelines to the template patterns, shown in red, 3/8" from all of the seams starting from the center out and around the outside edges. This helps to position the fabric more accurately. Line up the first piece with the guidelines, then place the next piece in the finished position before flipping over to the sewing position. Since these are oversized they don't have to be lined up perfectly, but they need to be close. Before sewing, fold over on the seam line to make sure the unit covers the next space up to the guidelines. Use vellum foundations so you can see the sewing lines on the back side. After sewing, trim the seam to 1/4" and press. The seams will be pressed to one side instead of open.
{!-- ia0 -->QS126.jpg{!-- ia0 -->