The placement of Pokémon dolls and cushions, as well as posters, is somewhat restricted. In the bedroom, dolls and cushions can only be placed on top of the large carpet. In a Secret Base, dolls and cushions must be placed on top of a mat, desk, or certain ornaments. The smallest desks and mats cannot hold any decorations, but "large" desks can hold up to three and "huge" desks can hold up to six, while large mats can hold up to five. In a Secret Base, posters can only be placed on walls, and only where they can be directly seen (that is, not on a wall facing "away" from or sideways to the screen).
It is possible to trade decorations with other players. Trading can allow a player to obtain certain decorations that are otherwise unavailable in their particular game. For example, the Red Tent can be traded to Sapphire or Emerald (or the Blue Tent to Ruby or Emerald), the Emerald-exclusive decorations can be traded to Ruby or Sapphire, and the Regi dolls can be traded from a Japanese version of Ruby or Sapphire to a Japanese version of Emerald.
The Secret Base PC can hold a certain number of each type of decoration. Multiples of any decoration can be obtained, but they do not stack, so that, for example, two Small Desks would take up two desk slots.