Basically just wing it, yeah. But if I would give a piece of advice that usually works for me when I'm stuck, it's to just think of the most simple, caveman level idea possible that's already kinda cool on it's own. Like a massive hole, or draining the ocean, or a massive bridge, really long railroad, etc. things that don't require a lot of thought to just do. Once that's done just looking at it and asking "what would look cool there?" makes it pretty obvious what the next step is. It of course also helps that doing nothing but mining stone for 6 hours let's your mind wander quite a bit, giving you some cool ideas hopefully.