I'd love to learn more about creating a document ready to print with embossing or a foil on it. By researching this, I've found that making a die cut or foil is like making a spot colour for printing. It requires the designer to create a spot colour which the printer will then make a plate for this layer, just as it does for cyan, magenta, yellow and black. It's best to name the spot colour in the swatch what you intend it to be, for example 'silver foil' if you intend to have it create a silver foil.
To ensure the foil/die cut is correctly applied, you can view the separations panel by going Window > Output > Separations. It Should appear as it's been named, for example as 'silver foil'.