We set up and assign orders to shipping boxes, input weight and box dimensions, and carriers before picking and packing.
Our suggestion:
1) In shipping box option, allow shipping box weight to be entered so that it automatically adds that weight to order weight total.
2) In shipping box option, allow box volume (cubic volume) to be entered.
3) Allow each product to be assigned with a cubic volume value.
If these features would be in place, an order with 5 different sized and weighted items could automatically be assigned to the best fit shipping box and then also have the weight of the shipping box added. Now that we have the order total weight, what box it will be packed into, we just need to select the best carrier service and then print!