try not to sit near a toilet, you will have people queing up next to your seat the whole journey, especially if you have an aisle seat.
As a couple who travel quite a bit, we always sit oposite each other in asle seats, its far more comfortable than jabbing your elbows in each other whilst attempting to eat the awful food served and you are still near enough to chat.The first time we were allocated seats like this we were outraged at not sitting next to each other, but half way through the flight we realised how much more comfortable we were and 20 years later still do so.