If you are bringing a computer, don't pack it in the main compartment of your carry on suitcase. You have to put it in a separate bin and it a pain trying to deal with your 3-1-1 bag, shoes removal and having to open your carry on all the way to dig out the laptop. (Did that once - never again!)
I put my 3-1-1 bag in the outer compartment of my carry on to make it easier to get to when going through security.
I also had a roll of pennie/quarters for pressed pennies and put that in the outer compartment of my carry on so I could put it in the bin with my 3-1-1 bag. Saves having to get the carry on searched when they see the bundle of what looks like metal.
Wear your heaviest shoes/shirts/pants on the plane. That will help keep your carry on lighter and save room in it.
When you are going the weather is going to be up and down. Keep an eye on it. I had pre-packed for my end of Nov. 2010 trip based on the weather a week before leaving and it changed drastically within a few days. Luckily I was watching the weather and could re-do my packing.
Bring a sweatshirt each, hoodie (wear this on the plane), 3 long sleeve t-shirts, 4 regular t-shirts, a pair of shorts, gloves, hat, extra pair of pants, swimsuit if you hope to go swimming. That way you've got layers you can take on and off as needed.
And you can do laundry if you need to. That's how I made myself take a break one day. I had to get some clean clothes.
If there is a certain kind of cold medicine you need, bring it with you. You may need it. When I needed some, all they had in the resort store was the "feds" actifed and sutafed. Neither of which I could take. I had a miserable last day with no cold meds since I didn't have a car. At least they had Vicks cough drops.