[masraum]

I am generally a very warm person so cold doesn't bother me much, but most folks find planes cool. Wear something comfy, and I'd go with long sleeves and pants.

Take head phones, even better if you've got something with active noise cancellation.

On planes I generally eat and drink as little as possible so I don't have to deal with using the facilities, but you're going to be on a long flight so you'll likely need to eventually. Still, I'd do what I could to minimize the need.