The most important thing to do initially is to be sure you are stitching a scant 1/4" seam and maintain that throughout the quilt piecing. Trusting a quarter inch foot to give you that won't work. I don't know the size of your strips that you are using for this Log Cabin quilt...but if you test sew for instance three strips of 2 1/2" strips the middle one should measure 2" if you are stitching a scant 1/4 seam..if that measurement is off even an 1/8" one way or the other by the time you've finished piecing your block will not be correct. Adding to that by the time you piece and join a whole row you can imagine how much the row will be off.
I can't stress how important it is to do a test sew first.