I only ever ask two things of flight attendants:
1) Please give me a seatbelt extender--I'm perfectly happy to wait until after the safety briefing, but I really do kinda need it before the plane is cleared for takeoff.
2) Don't treat me like I'm dirt because of my size. This includes telling me to fasten my seatbelt because the plane is about to take off (and then ignoring me when I say for the fifth time "Ma'am, could I please have an extender? I really do need one"), then finally dumping the extender in my lap like it's a chunk of radioactive waste after another passenger comes to my aid and politely reminds you that I'd asked several times for an extender.
A little respect would be nice, flight attendants. So what if I'm twice your size? I pay for my seat--I even pay for an additional seat if it's going to be on a small plane, so that I don't have to worry about anyone feeling "crowded" because my thigh is touching theirs. I don't cuss at you, I don't treat you like you're subhuman because you're a "servant", I don't beat you over the head with my status as somebody with a shitload of Frequent Flyer miles with your airline, and I sure as fuck don't get rude with you. I treat you like a human being who is worthy of respect, and I'd appreciate a little respect in return. I don't think it's too much to ask.
And if you can't manage that, then don't be surprised when I make a beeline for the counter at the gate (if it's occupied) so that I can politely ask how to get in touch with customer service after I get off the plane.
I cordially invite you to masticate my prodigious posterior,
The fat chick on the St. Louis-to-Raleigh leg of her last trip.