I have studied this in detail and have concluded:

1) people of all different shapes and sizes fart - you cannot tell who will be a farter when they sit down next to you.
2) If you have the ability to belch quietly then this is a good way to minimise farting.
3) covering yourself with a blanket when farting makes little or no difference to the smell.
4) waking someone up and saying "I'm really sorry but please could you go to the bathroom" does not go down well but is effective.
5) The Boeing 777 has vastly superior air circulation to older Boeings and this makes a huge difference. I am yet to study Airbuses.
6) I tend to be "messed up" for a couple of days after a longhaul flight. The more flights, the worse it is. August saw me take 12 flights, 4 longhaul and there was some serious ugliness after that.
7) I just farted yet am not on a plane. I do live on the 34th floor though and the escalator moves fast.
8) if you make poopoo before the flight then your farts do not smell nearly as bad.
9) If you are sat next to someone wearing this t-shirt then just pull down the oxygen mask and breath through it for the whole flight.
10) If you do get caught letting one off, either through sheer volume or a smell that lingers and clings to you then grab the airfone handset and shout "speak up Mr Brown, you're through now" and sit there in glory as all the other passengers refuse to believe someone can be so shameless.