The Ohio Star block is probably one of the most common and well-known traditional quilt blocks. You can find many variations, including the Maverick Star, which is currently all the rage around the internets.
This block is easy to make, so long as you pay attention to the details. It's built on a simple nine-patch block, with quarter-square triangles thrown in.
Fabric A, B, C
Step 1 - Cut as follows
Fabric A: 4.5 x 4.5 (cut four), 5.25" x 5.25" (cut two)
Fabric B: 5.25" x 5.25" (cut two)
Fabric C: 4.5" x 4.5"
Use your ruler to mark a diagonal line across your two Fabric B squares. Make sure your 45 degree mark is lined up with the edge of your fabric.
Pin your marked squares to your 5.25" Fabric A squares. Create half-square triangles by sewing 1/4" on either side of your marked line. Cut your squares along your marked line and press seams toward Fabric A. You should now have four squares.
Mark a diagonal line across two of your pieced squares (the same way you did in step 2).
Pin two squares together, seam lines matching (not intersecting). Make sure that you don't pin two same fabrics together. Do this for both sets of squares.
Sew 1/4" on either side of your marked line for both sets of squares. Cut those squares in half and press seams to one side. You should now have four squares made of quarter square triangles.
Lay out your block and make sure that no fabric is lined up next to itself. Ignore that my purple square has transformed into a grey square.
Sew blocks together into rows. Press seams in alternating directions. Then, sew rows together to create your block. Press your seams whichever way they want to go. Voila! You are finished. Gorgeous, right?