Ummm, it somewhat depends on what I have available for a post. For example, if I can' t think of anything better to round out tags for my #photography #nature posts, I go ahead and put #photos in there.

However, when I am able to use tags for 'multiple genres' I do. My thought is that it's likely the same people looking in photography and photos. But I could reach a larger audience by combining photography and story (when both tags apply.)

I hope that answered you're question..I was kind of guessing if that's what you were looking for. Feel free to tell me if I didn't understand the question.