It takes practice to sew a quarter inch seam. There are a few things I have found that helps me. Get a roll of the blue painters tape and cut a thick hunk off the roll about a inch long. Now but a quilting ruler under your needle so it lines up the 1/4" and stick the tape on your machine. Now you can butt the edge of the fabric against to keep a straight. Also it has helped be greatly to purchase a Sew Steady table for my machine( Great investment). I also press my fabic with startch. Practice, practice, practice.