In Italy, roughly 70% of households have a Bialetti Moka Pot. And chances are you have one too. But are you using it the right way?

https://www.youtube.com/watch?v=BfDLoIvb0w4

Here it is in text, if someone wants to save it :)
Constants:

1. Boiling water in the boiler
2. Full basket of coffee
3. Avoid sputtering phase by cooling down the chamber under cold water

Variables:

1. The lighter the roast, the finer the ground.
2. Less filled boiler will brew a bit earlier. Usually, dark roasts -> a bit less water, light roasts -> full boiler
3. Preheat the hob/relatively low heat on the gas hob
4. As soon as the liquid starts to flow, turn off the heat. For electric hobs, move it to the edge of the hob.

Troubleshooting:
If the sputtering phase starts before you think it's time (not enough coffee out etc):

1. Too fine of a grind
2. Too much heat