First of all, other than a laptop, jacket, carry-on, etc., you do not have to leave ANYTHING at security. If it is a ring, for example, you can usually wear it through. IF it trips the machinery then one is generally wanded.

Do you think, for example, that all those people with so-called "body jewelry" actually remove it? I am sure some do and a lot of others don't.

If you are in fact, FORCED to remove anything from your body AFTER you've been through, make certain there is at least one witness present.

But, seriously, I think what you are already doing is fine. I remove my wristwatch and a very heavy wrist bracelet and put those INSIDE my zipped and locked backpack before it goes through the machine. I do this just to avoid the wanding process which inevitably occurs if I don;t remove those things.

I wait to go through the scanner until my backpack is inside the scanner, too, and I watch it as soon as it emerges on the other side. No issues thus far.

I guess the main thing is to prepare before you get to the security point. You see so many people going back and forth,holding up the lines,taking something else out each time. Some items are unavoidable but anything you think may set the scanner off, take them all off, put them in a small bag,then place that bag in your carry on bag,jacket pocket etc. Wait on one side,till the bag goes through,then pass through. If you are then scanned again turn around to face your bags. And dont take so much carry on luggage,much easier.

Mt titanium watch sets of the alarms, so that goes into my camera bag before I even get to the security queue. My laptop also comes out before the queue and my camera bag is then locked.
If I'm on my own then I wait until it goes in before being scanned myself. If I am with my husband one goes ahead and the other waits with our stuff until the first one is through.
I have had to have my camera bag rescanned a couple of times, which is a pain. I tell them it has a few thousand euros of stuff it in and usually they allow me to unpack it into a tray and watch it while it is all rescanned. If my husband is with me he watches it all too.
I always remain friendly and understanding with the staff when they want to rescan. They have a job to do and aren't just being bloody minded. A friendly approach makes a big difference to how you are treated.