I'm working on a new quilt that calls for half square triangles that are 2" before sewing together. Each of these started out at 2". The middle of the quilt called for 12 squares across by 15 squares down. I sewed them 12 to a row and then started sewing rows together. It's not too badly off, but doesn't lay completely flat. Should I have sewn them in squares, say 3 down by 4 across and then together, rather than having a long row of 12? Would that have helped keep them more square? Thanks for any advice.