"Mr Stiff" - eww, come on, that's really clutching at straws to fill your copy quota, even more than a man drowning in a sea of light turbulence ...
I used to think I had it down to a fine art. Admittedly only on short haul - but on Ryanair when online check-in meant priority boarding, pick a seat near to the front where an older traveller had stalwartly placed himself in the aisle seat - chances were that with 2 grumpy old f***ers and being so near to the front all the gadabout trippers would carry on traipsing down a bit to find the perfect seat that Destiny had in store for them ... many times ended up being just the two of us in the row on a packed plane. I saw other regulars getting up to similar tricks ...
But sit in a window seat on your own and guaranteed that Fatso would make a beeline for you as being an unimposing, amenable type to sit next to ...