If you want to create your own base board, import or copy the tile to the .custom tiles database in the tile browser. The properties of tiles from manufactures are locked but can be edited if copied and paste in the custom database.
Browse through the 3D profiles and select one.
In menu Tile you can place the skirting board with the help of Wall Board Assistant. Press the button and start a new board. Drag and drop the skirting tile. If you want you can fill the whole board with tiles or you can add material to the wall.