I know now which items I shouldn't wear when I'm travelling by flight.
With that I mean avoiding things that make the alarm beep as you walk through the detector. I don't like being patted down for the body search, so I avoid it as best as I can. Maybe I'm just a little paranoid on being searched, not that I have anything to hide :P
Based on past experiences, I found out that the buckles on my red and green belts trigger the beep, hence no more travelling for these two. As for footwear, I have yet to be asked to remove them as most of the time I am wearing my selipar. A friend who wore heels had to remove them when we went through scanning at Ngurah Rai airport in Bali as it made the scanner beep.
When going through the security screening, except for the boarding pass and ID, I chuck everything else into my hand carry or backpack, including the camera and handphone as I prefer to have everything scanned in one go. There was one time I forgot to take out my pedometer from my pocket, which raised a little bit of curiosity and a few questions, but after I explained its functions they let me go. Phew.
Heavy jewellery and body piercings can also cause the alarm to go off. Oh, and for the ladies, some underwire bras can trigger it too. However, TSA's website mentions that gel-filled bras are permitted through security clearance and aboard the aircraft.
I wonder how they detect those : the gel-filled bras?