Welcome to the community!
The first thing to note is that if you tell it not to do something, you’re actually increasing the probability of it happening anyways.
So my first suggestion is generally to remove any mentions of what not to do. Instead, try to find a creative way to express what you want specifically, without mentioning any exclusions.
Similar topic: getting rid of the t-shirt in a t-shirt print generator: Crafting stylized t-shirt image design prompts