I feel like one of the things that separates a good tarot reader and a great tarot reader is their understanding of the relationships between the cards.
I've noticed with a lot of the newer tarot readers that I see around is that the tend to focus on only one card at a time. When doing spreads, they look at the question and the card and say "this equals that", like everything is just a bunch of straight lines, when, in reality, it's more like noodle soup. Lines are connecting everything in more than just one way.
Not only do you have to connect the question to the card, but you also have to look at how that answer interacts with other answers you've gotten and how it'll affect your interpretation of the following answers.
It is always such a joy being there to see tarot readers evolve and grow, and I see understanding that a reading is much more like a private eye's cork bord than a cut and dry equation as one of the fundamental milestones a reader has to pass in order to truly provide excellent readings.