Here's a tip about ordering, especially on short-haul flights. You can place an order the moment the wheels get off the ground -- which is often 5-10 minutes before they announce that you can place an order.

One thing to note, though: the offerings that appear to be available when you board the plane and are at the gate do not always coincide with what's actually offered. The moment the plane lifts off, the selection is updated to reflect the actual catering (and this usually means adding items to the menu as opposed to deleting them).