Two musts if you can :-
1. Make sure you have a window/aisle combination. It would be much better than 2 of the 4 centre seats.
2. If at all possible try and get the bulkhead seats (i.e. the ones immediately behind the dividing partition with Club). You get nobody leaning into you and a little more leg room.
[I have just realised that on a 747 - as opposed to a 777 - you cannot achieve both. I will leave it to those who have done this on a 747 to express their preference]
Also advisable to find out the confugration for the planes you will be on and keep as far away from the galley as possible (to avoid noise).
Finally, remember that the food is only basic economy so not much cop. Take plenty of your own snacks etc.
[This message has been edited by Frequentflyer99 (edited 10-17-2003).]