There should be no sex content in kids' cartoons. The industry has strict guidelines and standards to protect children from such inappropriate themes. Cartoon creators are well aware of their responsibility to provide innocent and educational entertainment for kids.
I think having a clear theme and a good understanding of the topic you want to convey are essential. Also, strong drawing skills and the ability to use humor or satire effectively can make the cartoon stand out.
The main difference might be in the themes and content. Futa docking manga often has more unconventional and adult-oriented elements that aren't common in regular manga.
Coffee mug cartoons often have cute and funny designs. They might feature coffee-related elements like beans, steam, or coffee cups with unique expressions.