Stabilizer
I also use stabilizer under my applique. I prefer wall liner by the roll from Lowe's or Home Depot since I do very large applique quilts and hangings and this is a very cheap source (about $14 for a roll). When you lift the presser foot to readjust the piece you want the needle to start right next to the last stitch so there is no gap in the stitches. To turn a corner, restitch from the top right over the stitches that you just made. For a point make sure you stay on the fabric and don't stitch off on either side. Rember to keep your stitches perpendicular to the piece as you go, this is why you have to keep repositioning the needle as you go around a circle. The smaller the circle the more you have to reposition.