Your last step is to square up your half-square triangles. I squared mine up to 4 1/2". I could do that because I took a scant 1/4" seam allowance. You may need to square yours to 4 1/4" or 4" square. Square ALL your half-square triangles to the same size--either 4 1/2", 4 1/4", or 4".
Get your half-square triangles done and stay tuned for LOTS of ideas on how to use these half-square triangles. I'll be posting some suggestions on Thursday (when the virtual retreat starts).