I can't use magnets because half the time I'm wearing my suit, I am DJing and scared to death of erasing laptop hard drive with magnets (which I know it's shielded against, but it's how I pay my mortgage, so I don't wanna lose anything). I have a combination of velcro and snaps. I buy double the velcro: industrial stick on hooks for the armor and sew on loops for the vest. All the corners are snaps with the velcro in between and the more tricky places. Shoulders are just velcro, never had a problem with my horsehair braids getting caught in there.
I have to do a lot more because I still don't have a real flak vest. I'm on my second "t-shirt vest" which is super inaccurate, but a lot cheaper (just hem up the bottom and sleeves, then cut the back and re-close with snaps). It's light and stretchy material, so keeping the armor where it needs to be takes a lot of attachments and some support on the inside. One day I'll get a real vest, but this thing is hot enough with a t-shirt over the flightsuit. Also, that's still below "build a jetpack" on my to-do list.