For the basic art style, I might say "bold graphic art style illustration bright and saturated ..."

Then for the central object and background and the colourway I might say "of an orange fantasy castle on a nondescript orange hill background..."

I'll try prompting composition "centred in/left of frame".

I might vary that several times until I have a good basic image to start working with.

Then I get into the editor and start masking off areas and regenerating them using seed images.

So for the workflow automation one I googled "elaborate machine with gears and screens" to find a suitable reference, and dropped that into the prompt with text "elaborate orange machine".

I find its very hard to get correct any secondary objects (frog with pick, octopus with sign, etc) or specific impressions (smiling eyes) in a single prompt, and so masking and regenerating the area is always better.

Hope that helps!