I just went to a quilt show judging last week. The judge we had said even it there are no curves the binding should be on bias because it will wear better in the long run. It should be hand sewn on the back using a ladder stitch. The corners are to be a perfect 90 degree miter and the little flap from the miter corner should be sewn shut. The binding should be full of batting and if it not she advised to cut little strips of batting and lay in there to fill it when you are hand sewing. If it is full of batting it will wear better. Now, if you not showing a quilt and it is for kids to run around with I would machine sew if you don't enjoy hand sewing.