The basic logic of Tarot magic can be explained as simply as this:
If you think of a spell ingredient as something conceptual rather than
something tangible, then it makes it a lot easier to think creatively
about what you can use.
One item that many of us have on hand is a deck of Tarot cards. While
we often turn to them immediately as a method of divination, a lot of
us tend to forget that we can use them in spellwork. After all, a
Tarot card – whatever it may be – symbolizes some aspect of the human
existence. More importantly, you’ve got 78 cards to choose from. If
you’re someone who uses reversals in your Tarot readings, that means
you’ve got 156 symbols, or archetypes, right there at your fingertips,
just waiting for you to unleash them. By selecting a Tarot card that
represents your goal, or the intent of the working, you can craft a
simple spell that’s just as effective as one with all the trappings
and bells and whistles.
Of course, now you have to delve into symbolism and patterns embodied in Tarot.
Let's start with spells concerning matters of the heart.
For matters related to love, family, emotions, and relationships, you may want to choose Cup cards as your focus. Consider an Ace of Cups to represent new beginnings and starting over, a Three of Cups to symbolize celebratory events like births or weddings, or the Queen of Cups to stand in for a sensual and captivating woman. The Lovers card, although associated with love and all its trappings, is one you may want to use if you’ve got a decision to make between two potential romantic partners, or you’re trying to help someone (including yourself) overcome temptation. Cup cards can also be used to represent the element of water.
If that's not enough, violent action is all the rage. A mainstay of entertainment.
Sword cards are associated with air, and they’re all about conflict. These come in handy if you’re trying to do spellwork that is damaging or destructive (as always, if your tradition forbids cursing or harmful magic, don’t do it, and you can just skip over this paragraph). A Three of Swords can bring about heartache and pain, particularly if there’s some sort of love triangle involved. Use a Seven of Swords to represent a deceitful liar in your life. The Knight of Swords will reveal the truth to those who need to hear it, whether it’s something they want to hear or not.
Essentially a Tarot-based magic system is all about taking a symbolic system and deploying those symbols to cast the spells you want.
The bottom line of using Tarot cards in spellwork? If you familiarize yourself with the meanings of the cards, there’s no reason you can’t craft a perfectly useful spell with the deck you have on hand. Think outside the box, be creative, and see what you can manifest!
Source: Tarot Card Spells
One word of warning about tarot magic.
Never use the same tarot deck for magic and for prophesy.
You can use one tarot deck for magic and one same for divination if
you want, but they should be two separate decks. The rationale is to
avoid creating unwanted results while trying to foresee the future.
Source: Tarot Magic & Spells
More can be found about Tarot magic by using a search engine and entering the search terms "Tarot magic". This form of divination is not infallible, but it does work wonders.