Like the others here, 1/4" seams can sometimes be the pits. I also use a dam to have the fabric butt up against to keep the pieces from wobbling. (I use a whole pack of sticky notes aligned on the 1/4" seamline. It also helps if your machine is down inside the cabinet so that you have a flat floor to sew on. I tend to wobble when my machine is on a table without its flat table.