Here’s the best way to accurately cut out stripy fabric. This technique also eliminates any wobble or mismatch of the stripes. Each pattern piece should be cut individually. The stripes should always match at the side seams and you can choose how you want them to look on the shoulder seam. The shoulder seam usually sits on a sloping angle of some sort so it will create a chevron to a certain extent. If you’re using a stripe of equal width in two colours this shoulder line choice can often dictate which is the dominant colour to sew the garment in!