Gareth Edwards tried to make this film as traditionally as possible. In preparation for filming, he visited a virtual reality studio and was confused by seeing a poster explaining the process of filmmaking on the wall. Upon inquiring why such an obvious poster was on the wall, Edwards was shocked to find out that it was over 100 years old. Edwards then decided to take a different approach and talked the studio into letting him film without green screen, and filming on-location, using smaller cameras, using guerrilla-filming techniques, employing Industrial Light and Magic and then adding in the sci-fi elements later.
On September 19, 2023, Edwards revealed that he initially planned on having a company specialising in AI-generated music replicate Zimmer's style of music. Although the process gave him satisfying results, Edwards instead chose Zimmer to originally score the film. The soundtrack was digitally released by Hollywood Records on September 29, 2023.
Gareth Edwards left the most emotional scenes until the end so Madeleine Voyles could build a strong relationship with John David Washington. "Madeleine's a very quiet, shy girl," Edwards said. "It's really hard to become her friend. I tried the entire movie, and I think she let me a little bit in, but not fully. But [John David] cracked the code and became like a big brother to her--and her best friend." The two were "inseparable," Edwards said. After wrapping a take, when Washington would walk off set looking for some quiet time alone--"trying to keep in that headspace before you do the next take"--Voyles would simply "run after him, hold his hand, and start talking about a toy she really likes. And he's such a sweetheart, he'd go down to her level and start getting really excited about what she was saying."
Director Gareth Edwards wrote the protagonist character specifically for John David Washington after seeing his performance in Monsters and Men (2018).
After seeing hundreds of kids from around the world who sent in audition tapes to the open casting for Alphie during the pandemic, Gareth Edwards met with Madeleine Yuna Voyles. At her in-person audition, he said, "We were just trying not to cry. It was so emotional and brilliant. And I just thought, 'Okay, this is too good to be true.' And I got paranoid that it was a one-off thing and it would never happen again." To challenge the young performer, "I invented this other scene and she did something even more heart-grabbing. And I was just like, 'Okay, this is it. This is our kid.'"