Sunrise, I made a triangle template instead of buying a new ruler to cut the dark triangles. I know some people started sewing with the strips & Strings they had on hand, & planned to continue as new strips joined their collection as they made other quilts. I didn’t use a foundation paper or muslin. I cut side pieces to fit alongside the triangle & sewed strings to fit that space. Mine worked out well & I used all my triangles & the Strings I had up to that point.