I am a fan of tearing fabric. As quilters who are not necessarily garment sewers we often forget about straight of grain. It makes a real difference in having your fabric lay straight and true. I make a lot of charity pillowcase dresses from gently used sheets. It really annoys me that they are often not made on the straight of grain. I can use the hems already in the sheets if I cut or tear the fabric just right. Often if I tear it I discover that the decorative hem at the top of the sheet was not applied on the straight of grain as the part I tore almost never runs parallel. I worked for about a year in a shop that did custom dressmaking and alterations. I learned a lot there. Creating things taking into account the straight of grain makes a huge difference in the quality of the finished product.