It depends. Do you feel like you have a consistent divine presence in your life that you're working with, like you're trying to find out who your patron (more or less) deity is? Or is the communication you want more general?
Either way, I think it's the kind of thing you tease out over time...see what themes or symbols reoccur in the cards, maybe even across different decks. Like maybe eventually you notice that you keep on drawing cards with recurring details, even if it's not the focus of the image--like, say, spiders in the corners. Then you see if you feel drawn to any deities associated with spiders, and so on.
And of course, it also depends on the tradition you're working in. If it's one that has a deck in the right "flavor" out there, that might help. Not all traditions have decks out, though.