Let’s start with the stuff that most people will agree with: Krypton.
The opening of “Man of Steel” was absolutely fantastic. This was a real world and it showed in every detail. From the landscape to the science and politics, Krypton felt more real than any other iteration I’d seen on screen. Also, the little time we spent with the characters while still on planet really helped sell the relationships and drama later on. I wish there had been more, and I would love to see some flashbacks when we get the next solo sequel. They could easily set up Supergirl in that flashback as well.