Yep there are some tricks to it, and it's not easy to get things to come out exactly as you envision! I've been having a blast experimenting with the AI art tools, I enjoy it almost as much as writing.

Side note if you're interested. I believe the reason why it's so difficult to do "take this image and change this one thing" is because it will take an image prompt, convert that into a text description (which loses a ton of information) and then add your new prompt, thereby generating a new image. There are eraser tools you can use to remove a section, to redraw. I've had some better luck with those, although they sometimes have trouble keeping things contextually consistent with the overall image. Also recommend looking into the computer algorithm they use to generate the image, it's nearly magical to me how it works, and I have a software developer background!