You could do cross hatching. Draw a straight line from one corner to the opposite corner and stitch. If you have a walking foot with a guide then just put your guide on the line you just sewed and stitch the next line and etc. If you don't have a guide then just draw out the lines and sew. Then go from the other corner and draw to the opposite corner and cross the lines you just sewed. Cross hatching.
I hope I explained that right.