Usually it’s recognition of the dream that let’s me manipulate the dream more actively.

Keep a dream journal, do reality checks often in waking life and you can maybe start realizing mid dream that you’re dreaming. Usually it’s at that point I’m able to take more control of the dream.

I say more because it’s rare that I have full control of a dream. Like I might make myself fly in a dream, but might lose grasp of the setting that I’m actually flying in.