Captain America: The First Avenger
The studio ensures directors are open to the idea of the shared universe and are willing to include connective material, such as Kenneth Branagh and Joe Johnston needing to include "Avengers" set-up scenes in "Thor" and "Captain America: The First Avenger", respectively. Marvel Studios usually has a big idea they would like to explore or build to in a project, such as Hydra infiltrating S.H.I.E.L.D. in "Captain America: The Winter Soldier", with it up to the filmmakers to interpret and "improv a little bit" to get there. After these ideas have been developed, the creative team then begins to explore ideas happening in other future projects to see how to make any larger universe connections. There was large amount of collaboration between the Russo brothers and writers Christopher Markus and Stephen McFeely with the other Phase Three directors and writers to make sure "everything line[d] up right" for the MCU's "culmination" in "Avengers: Infinity War" and "Avengers: Endgame".