1. If you cannot find your seat without the assistance of a flight attendant, you should probably not fly. This rule goes double for anyone who is holding an economy class ticket and slows down in business class just to make sure that their seat isn't there.
2. If you are flying in economy, act like it. I know it would be nice if we could all fly first class, but we can't nor do most of us pay for it. So, if you are sitting in economy, don't act like a jerk when the flight attendant tells you that they don't serve drinks prior to take off.
3. When the flight attendants ask you to put your tray table up and your seat in the upright position, just do it. It won't kill you to sit vertically for that first 10 minutes and last 10 minutes of a flight.
4. Be considerate of other people on the plane. Not everyone wants to hear your conversations, and some people are actually trying to sleep, so shut up or speak quietly.
5. When the plane lands, just stay seated until people start getting off the plane. From experience, you aren't getting off the plane any fast by standing up the minute the plane lands.
6. If you can't carry your bag, it isn't a carry on. Please do not board the plane with a suitcase, the overhead and under seat storage was not meant for all of your luggage, just a few things you would like on the plane with you or things that you might need should your bag get lost.
Thus ends the suggestions I have for people when flying, but let me put this suggestion out there. I think flying should work like a reality television show. If enough people find what you are doing to be annoying or distasteful, you should be voted off the plane. This would mean that you would be immediately evacuated from the flight by parachute, or possibly put in the luggage compartment.