As Marvel Studios president and all around gift to humanity Kevin Feige told Coming Soon, this process involves a lot of meetings, watching films and brainstorming.
As such, Marvel looks at a lot of different names and goes through the careful process of narrowing the search down.
Fans love the characters and actors of the MCU, but the directors are just as vital to the formula, if not more so.
Then when they have a top choice, they make sure it’s someone they’d like to work with for the new three years (or more if they really like you).