1. Give enough room to your co-passenger
You are not the only traveller on board. So, make sure you are not using up all the space for yourself and your luggage. Also, if it's a short-haul flight, you may try and not recline your seat way too much. Let everyone have access to their respective seat, legroom and luggage space in the overhead bins.
2. Try talking less, for once?
It's time one realises that being a chatty neighbour can be a source of irritation for many, especially if the other is trying to concentrate on something more important. How about listening to music on your own, or reading a book? Else, enjoy a short, rejuvenating nap.
3. Pay some respect to the crew
If certain people can manage to be cordial, even after clearing your litter, can they not expect the same behaviour from you in return? You may say it's the responsibility of the air hostesses to ensure you have a comfortable journey, but it is also your responsibility to avoid causing unnecessary hassle.
4. Don't drink too much
Nobody minds a couple of drinks, only if one is not a drunk troublemaker. Drink only to the extent you can manage to hold.
5. Don't let your actions be an inconvenience
You very well know what qualifies for respectable public behaviour, and what doesn't. Things like bad odour (from food or body), littering the place or even hogging armrests lead to the inconvenience of other passengers.
6. Maintain a queue while boarding or getting off
If you have boarded your flight already, know that nobody is going to take away your seat. Nor will you be left behind in your seat, for the flight to take you on a free trip after landing. It's just a matter of a few minutes. Maintaining some form of discipline while travelling is not that difficult.