STEP ONE: Cut a strip of fabric 150cm wide by 50cm. (Don't worry about how the picture looks... it was a wonky scrap that I just used as it was)
STEP TWO: Cut two straps 8 cm wide by around 50cm long
STEP THREE: Fold straps in half. Sew along one side. Turn inside out using a safety pin
STEP FOUR: Wrap fabric around your chest. For me there was around a 45 cm overlap. Pin where it overlaps then pin down the front where you think the folds will hide it best.
STEP FIVE: (No picture sorry, I forgot!).... SEW DOWN THE LINE YOU PINNED. If using knit fabric, use a zig zag or knit stitch.
STEP SIX: Pin on straps and sew.