This is mostly so I remember things, but some readers might also find it helpful. Please keep in mind we do carry on only, so some of this is about that.

Don’t buy a money belt. You won’t use it.
Sneakers are fine, even with skirts (though I still cringe and haven’t managed to convince myself to go there! Soon … I hope … maybe.).
Bring a maximum of two pair of shoes, and probably sneakers and sandals are the way to go — the sandals can suffice for dressier shoes.
ONE hat, you idiot. You only need ONE, packable hat!
If you like a pair of socks, bring two pair — one to wear and one to wash. Or maybe three …?
You only need one pair of compression socks. You only wear them in the plane. (What was I thinking?!)
If you think, “I just might like this,” don’t bring it. “Might” is the key word here.
Despite the weight, do bring your electric toothbrush. You like it too much and the manual one simply doesn’t make you happy.
Grab the free toothpaste some hotels have in the room (so far seen only in Spain, I think), and grab the one offered on the plane if you have that option.
If something barely fits (the waist is just perfect) expect it to barely not fit somewhat soon! All that food …!
If you hate something you brought you don’t have to keep traveling with it. Just leave it.

And sorry guys … but women might be interested:
Bring three pair of undies: one to wear, one to wash, and one “in waiting”. Don’t need more and if for some reason you did you can buy them.
Two bras. That is all.

Oh … and these might only be for some iPhone users:
Fully close the camera app before putting the phone away. If it accidentally starts to run again the phone gets very hot and the battery gets used up.
Don’t put the phone in a pocket in the front of your bag/purse: the sun shines on the bag and the phone gets very hot.

Surely there will be more of these entries … not all packing related, but travel related for sure.