Generally underwires and light jewlery, zippers etc generally do not set of off the alarm. More often than not shoes set the alarm off and most women blame it on the bra. In most shoes, except the majority of tennis shoes, there is a metal support shank in the sole of the shoe. Having said that, if you wear what might be considered an excessive amount of jewlery & have a lot of zippers on you clothes some machines are a little more sensitive than others. I want to emphasize, if you alarm even your chest area will still be checked.
Wear tennis shoes, something with a zipper or not, a shirt without a lot of metal dangles and remove your belt if it has metal. I wouldn't suggest more than a watch, a ring or 2 and ear rings. Again the more metal you have on, the more it will pick up.
Hoep this helps.
Brian