I opted out on magnets for the shoulders only because my arms have way more movement, more likely to come off. The velcro and elastic are a good combo (for me). The chest stays in place, the ab piece is attached to 3 pieces of elastic (middle and sides) allowing for a little flex when walking n stuff
Sorry I don't have pics of the setup. I found the center of the vest and put the two snaps in place (pointing down, from the underside of the vest). The elastic runs perpendicular from the vest. If I get time I'll take a pic and upload it here