Haha! I love this one:

"Don't forget that if the person in front of you does NOT lean their seat back at all, you should give them a tip, too.

Likewise, if you don't lean YOUR seat back, you should expect a tip from the person behind you. Don't be shy about this - if the person behind you doesn't offer, just ask. Explain that you SPECIFICALLY did not recline your seat in order to make their experience more comfortable - in fact, more like a business class seat - and so therefore they should give you a tip. I have even used this money in the past to "finance" the rest of the tips for the pilot and stewards.

And don't forget to add 15% for any duty free items you may have purchased."