Order waiting shipments by ascending date
It is better to show first the first orders that need to be worked. For orders that are mainly created by user it is better to order by id descending so new orders are on top. Of course this is no more valid when displaying all the orders but in such case there is actually no right order. The user will choose one.
As there is a planned date and effective date, the idea is that ordering by effective date fallback to the planned date.