How to perform a tea cup or coffee grounds reading?

Hello, I often see people reading tea leaves on TV, in Harry Potter, Charmed, and other shows, and I would like more details on how to do it.
These days, they are all in bags or with the coffee grounds. How can one try the experience?
my regards

Good evening, Yerly

For preparing coffee grounds, it's not much simpler.

1. Place a pot of water on the stove; the amount of water will depend on the number of cups.
2. Boil the water, then pour the ground coffee into the boiling water.
3. Let it continue to boil until the coffee reaches a boil.

4. Pour the coffee into a cup without straining it.
That's called Turkish coffee.

et tu bois tout le café 'tout le café' il est tres corsé 
ensuite tu retourne la tasse sur la soucoupe durant 5 à 10 mn environ
le marc de ce café va secher au font de la tasse

Why turn over the cup you have drunk from, simply so that the coffee grounds left at the bottom of your cup form signs or drawings?
so that you can later interpret these
signs

There will be signs like that kind of
some traits
waves
you will be able to see spider drawings there

And all these signs have a meaning.
you will even be able to carefully observe astrological signs
lion's head or other

I hope I was clear to you

Rachida