exerda

I always wait until my last bin or bag is on the belt before heading through the WTMD.

Often, I use the following order:

1. Rollaboard: it's the heaviest, and largest, and I don't want it sliding down and slamming into anything like the bin with my laptop, etc. Plus, it will provide "padding" should something force my laptop through (like someone else's bag behind it), and "spacing" to keep my laptop from sliding all the way down the rollers on the other side of the x-ray (and possibly falling to the ground).
2. Bin with my shoes and anything else which must be divested at the checkpoint (jacket, etc.)
3. Bin with my laptop.
4. My laptop bag, closed up so things like cell phone, etc. don't have a chance to fall out. Also helps pad things if the bags behind mine slam into my stuff before I can retrieve it.

I'm usually quicker through the checkpoint than anyone except those traveling with no carry-ons or a single item without a laptop in it.

Now, I have had some TSOs try to insist I go through ahead of my stuff, but I have played dumb and ignored them. I'm not going to leave it where (1) someone could possibly take it while I'm stuck waiting for it; and (2) where the x-ray operator reversing the belt could cause something to fall (like my laptop or camera).