Is there a strategy to choosing the card used to construct a wonder phase?
Picking the right card often is an important strategic choice, and I think you've got a decent feel for the main part of that - use a card that you don't want yourself, and that you don't want your opponents getting. In particular, I would tend to look at the next couple of players that the hand will be passed to, and see if I can spot a card that is key to their strategy that I can deny them. Alternatively, if nothing stands out, I'll see if any of the cards I have is a duplicate of one they already have, and bury a different card, thus reducing their options.