My first real tutorial! I picked this block to do for my local bee. There is a great tutorial here, but it is for a 14 inch block and my block will end up 12 inches finished. Hence - my tutorial.
This tutorial has been edited as of 1/30/2012. Adding the triangle and trimming the block are now more clear.
Step 1. Cut a bunch of strips. Mine are between 1 and 3 inches wide. They need to be about 5 inches long.
Step 2. Sew the strips together into one long strip. Press the whole thing.
Step 3. Cut a section of your strip off at 9.25 to 9.5 inches (depending on where your next seam is).
Step 4. Trim one side of your new strip just barely.
Step 5. Trim the other side of your strip so that it measures 4.5 inches wide.
Here's your trimmed strip. Ready for triangles.
Step 6. Get your background fabric and cut some 4.5 inch squares. Cut these squares in half diagonally. For 1 block you will need 4 squares and you'll end up with 8 half square triangles.
Step 7. Use pins to mark the center of each side of the strip.
Step 8. Place your triangle centered on the strip as shown below and sew them together using a 1/4 inch seam. Place another triangle on the other side of the strip in the same way and sew.
Step 9. Press both triangles to the sides. You'll have a block that looks like this.
Step 10. Trim your square. This can get a little tricky since you need to make sure the strip is centered diagonally in the square. I used a 6.5 inch square ruler I got from JoAnn for less than $5. I marked it with tape 2 inches away from the center diagonal line on each side (for a total of 4 inches) - like shown below.
You do not have to use this type of ruler, just keep in mind that you'll want your row of strips centered diagonally or your block won't turn out right.
Place the ruler over the block and line up your tape lines with the edge of the strip.
Trim around the whole thing.
And there you have your first block!