I plan on covering my foundation with pebbles but I can not do it right now because of the walls. I am not sure how much of the foundation will be covered by the bottom edges of the walls so applying the pebbles now might impede the walls from fitting properly. So it is best to leave the application of any foundation covering for later, even if you're just using a printed paper. Your paper can become damaged with glue and paint when you assemble the dollhouse walls.
Binder clips will keep the butted together foundation pieces straight.
