Hi Judy,
The quilt in this post starts with 10″ squares, so the triangles will be even larger than your quilt starting with 6″ squares. If the triangles you cut from 6″ squares look too big, you can go with smaller ones. Coordinated sets of 5″ squares are easy to find, or you can go even smaller, to 4″ or 3″ squares. The smaller the square you start with, the fussier it is to cut and sew the triangles, and the more triangles you will need to make a quilt of any size. I like big squares because they make for easy cutting and sewing, but you don’t have to limit yourself to what I like.