Generate Random Layout

I am currently creating a 2D game like Angry Birds in Unity.

In this game, there are no levels, so the collection of pigs, boxes, gifts, and other things are on the right side of the game and can change layout.

Right now, I am manually creating this gift layout, so I insert each object one by one and position them myself, but it seems inefficient if we want to create 1000 different kinds of layouts (which would take a lot of time).

Is there a more efficient way if we want the layout to be generated by the system?