Symbols and image are the language of the soul and the intuition. Tarot is an elegant system of symbols and images that is designed to access the intuition. The challenge of working with Tarot is decoding the cards' images to the matter at hand.
Since it is often difficult to bring up the soft voice of the unconscious directly, the images of the Tarot act as a proxy. But then you have to link the Tarot's images to the message that your unconscious is trying to tell you. Sometimes the messages are very obvious. You have a flash of intuition and there it is.
And sometimes the symbolism is very obvious. If you are asking about whether a new person is about to come into your life and the Two of Cups comes up in the appropriate place in the spread, then the answer is a resounding 'yes.' A Page of Wands might indicate that a relationship is about passion with little staying power.
Some messages are more subtle. It is common to do some 'teasing' out to get at a card's meaning in the particular circumstance of your reading.
Sometimes you will see a detail in a card that gives you a significant clue so it is important to take note of what grabs your attention and note its meaning to you. The black cat at the foot of The Queen of Wands may represent your pet or it may refer to the Queen's instinct.
Because the cards are sets of symbols, they may operate on several levels at once. The Queen of Wands' black cat can represent both in the same reading. Context is important. The Sun might indicate the attainment of success or it could describe your upcoming vacation in a warm, sunny clime.
If you are choosing to use a spread, meaning that you are using more than one card, take note of the way the cards' images interact with each other. This powerful technique was taught to me by Tarot scholar Robert M. Place. For example, the Knight of Cups faces the right. He is going towards the people or the issues represented by cards to the right of him. But his back is turned to cards to his left.
How do you know if your interpretation is correct? If it resonates with you then you have the validation you need. It is not necessary that a given interpretation hews to the definition laid down by an authority. While your unconscious absorbs the messages of the culture in which you live, ultimately, it speaks a language individual to you.