I don't own many decks of cards.
A deck has to really grab me, it has to be love at first sight. Otherwise the cooperation will not be productive...
But how do you find the right deck?
The cards have to resonate with you, even at first glance the imagery has to trigger something deep in you. And you should of course be clear about whether you would rather have a tarot or an oracle deck. Or something completely different, such as Lenormand.
There are countless beautiful oracle cards on the market, but I find that they are more useful for more general questions and as impulses. If it should or has to go deeper, I would always use the tarot cards. Precisely because of the person cards, relationship patterns and interpersonal relationships can be better represented here.
Then, when you hold your new deck in your hands, look at each card individually. This can also take some time. Feel what the card triggers in you, what associations arise. Always try to intuitively grasp the meaning of the card first. Feel free to take notes on each card, too. Only then look up the meaning in the booklet and see if your intuition was right. Maybe this will add a few aspects that you didn't recognize. But I'm sure the core message of each card can be recognized from the gut.