I also use a 1/4 inch foot and seam ripper to keep to the correct seam width. One thing I've noticed when chain piecing--I tend to reach for the next piece before I get to the end of the piece I'm sewing. This can cause me to "veer off" some. Now I slow down, reach the end of the piece I'm sewing and then grab the next piece to place. Hope this helps-oh, and keep practicing!