You should always do a reading before engaging in operative magical work. Always. Without exception. Sometimes, you may feel you know what the reading is going to say ahead of time, that the response is going to be positive in terms of your desired results. And you might be right. But even if you are, you want to go into the working with as much awareness as possible. Even the wise, wrote Tolkien, cannot see all ends—something that is definitely true when tinkering with cause and effect.
But how do you ask an oracle such a question and how do you understand the answer? You could ask a different kind of oracle, but when it comes to cartomancy, the first thing to keep in mind is that not all decks of cards are the same or are made for the same purposes. So-called “oracle decks,” are typically simpler than tarot, Lenormand, or playing cards and they are organized around a particular theme (like The Goddess Oracle or, my favourite, The Halloween Oracle). I do not recommend using those as they are typically oriented toward providing initiatory advice that will help the querent live a better life. That is excellent, but we need something a little more flexible and complex.
Instead, I strongly advise using a classic Rider-Waite version or some of the older European 78-card decks. Hermetic, Golden Dawn, and most Lo Scarabo decks are also very good, if you can read the imagery correctly. Also, Crowley’s Thoth deck is excellent for this, but beware that its symbolism and structure require dedicated study since Crowley’s interpretations often vary from the GD text represented in Waite’s books.
All decks of cards are oracular if we want them to be. With this in mind, I sometimes like to use a standard 52-card (54 with 2 jokers, which I also use if the deck has them) in a Neoclassical French layout. But as a general rule and when it comes to tarot, it is wise to avoid non-standard tarot decks when asking about magical work. You are doing this for a practical reason, not entertainment. So be conservative and careful in your approach.
You can get fancy with your question, but remember that the more “standardized” and repetitive your syntax is, the more your results will unfold in a reliable comprehensible way. Therefore, I often use the simple question, “What would be the outcome if I did magic to _________?” After decades of asking this same question before 99% of the magic I do for myself and others, I feel confident that the answer I get will be specific to that.
So what does a “positive” answer look like? We know that for the most part it will depend on the subject matter of the question. The tarot is a complete language of symbols that can respond to anything. Each answer will be unique, even if there are only 78 cards available. Still, certain cards are definitely favourable in this. Here are some general outcomes to keep in mind.
In the Major Arcana (the Fool through the World), the most favourable cards for magical work tend to be The Magician, the Empress, the Emperor, The Chariot, Strength, The Wheel of Fortune, The Sun, The Last Judgment, and The World.
In the Minor Arcana, aces, knights, and kings tend to be the best. The rest of the cards will depend on the context of the question.
It may seem exhausting to do this for every magical working, but you can really mess your life up doing magic capriciously and blindly. Think of a powerful magical working like a gun. You want to see where you’re pointing it and you want to understand as much about how to use it as possible.