Pressing is also important. Set your seam on the wrong side first by raising and lowering the iron (no scrubbing) and then press to the side from the right side making sure there are no pleats.
I also use needle position and sew a scant 1/4" as a "hair" of width is always lost in the seams as they pressed out flat.
Sticky notes also work as seam guides which I use not only for myself but for the little ladies I teach.
Suzanne