I have my routine pretty well worked out now, and wouldn't wear anything other than the following:
- Cotton trousers (More comfortable than denim to me)
- Light shoes (Usually a pair of Converse, doesn't get too hot/sweaty on long periods of time. Although I often remove my shoes on the plane anyway)
- A thin sweater (Just enough to compensate the cold cabin air)
- A T-Shirt (Because I am doing my own laundry and can't be bothered with ironing)
- Funny Socks - Sometimes (Have a laugh with fly attendants or the person next to you, why not?)
- An aviator watch and a ring (That's purely to compensate the fact that I clearly cannot be bothered wearing a Blazer on a plane, so I have to bring it up a notch at some point.)