When squaring up HST, I sew them into the square and put the 45 degree mark from my square on the seam line. I then square the one corner and 2 sides and then move the square to do the opposite sides.
However, if they need to remain triangles until you know where they go, they will have to wait until the pattern tells you their location.
Last edited by Tartan; 02-13-2018 at 11:20 AM.