The title doesn't really encompass all of my questions... After some thought I've decided to set my story in a semi-fictional modern reality, but I'm having problems with creating a distinct mythology with magical things and the sort, an explanation for the existence and the flow of magical energy, and so on... It feels like whenever I have an idea, someone else already did it better than what I had in mind, and I'm just copying. Harry Potter didn't even explain magic in its world, or why some muggle people were born wizards, but because it was initially a book for children, JK Rowling was spared an explanation. I want to give it an explanation, though. Another problem I have is with names of places and characters... For example, I want to name a demon, but don't want his name to sound cheesy, like I just took an existing name and twisted it, maybe something with meaning... And, finally, the creation of special, physical symbols (emblems, logos for example), is also something that's troubling me. For now I just have placeholders, but I'm afraid my knowledge of this stuff isn't vast... How to create a convincing mythology encompassing all the elements I've described above?