The example shows a 30 cm (~12") block from 36 five centimeter (~2") units. Using the PDF pattern you can produce 12 triangle units in one go.
Finished size is 5 cm (~2") plus seam allowances. If you are sewing in inch just cut the finished units to 2 ½".
Print the pattern on (thin) paper and cut along the dottet lines.
Cut two fabric pieces ~ 7" x 10". Place right sides together and pin the pattern on top.
As always with paper piecing: Use a size 14 needle and a short stitch length.
Sew all along the dashed line - in one go!
Cut along the solid lines:
First on the outer line; then horizontal and vertical.
Remove the paper now and cut from corner to corner between the seams.
Iron seam allowances to one side.
By the way: when your scraps are smaller you may also use a part of the foundation only.
Using the Quicker Trimmer it is very simple to trim the units to exactly 6,5 x 6,5 cm.
Of course you may also use a standard (inch) ruler with a 45° line. But always look twice before cutting! Highlight the correct lines on your ruler with painters tape.
Design Suggestion
For many great ideas on scrapy quilts including triangles go to Bonnie Hunter's blog.