I am a fan of cross-hatching. I use a serpentine stitch and sew in a straight line. Hides any crookedness! I use the blue painter's tape about 2" wide and line up my presser foot with the edge as I stitch. On this wall hanging, I did this, but used a double needle when stitching.
If you have never used painter's tape, do not stitch ON the tape. Ask me how hard it is to remove then!!