Beyond drawing the human, creature, and styles in manga, the most difficult thing to do is drawing the background. It needs the details, mostly and of course, time consuming. I realize that some manga-ka did not really draw their background or scenes. The manga-ka of Saishu Heiki Kanojo -- Takahashi Shin, put some city illustration based on real photo, in my own observation. It was so clear that the photo had been manipulated into dotties or lines. It seemed no real restriction that you really had to draw 100%.
The next tutorial I'm featured here is one way you can use to improving your lack (mmmm....) ability of drawing (or your laziness) but... don't preserve the laziness. Basically, copying the real photo into your drawing is just fine. It is part of progressing your drawing skills. I read a book of quick sketch of architecture, and it was advised to sketch by copying the actual photo.
So this is the background tutorial by theAlfier from deviantart.com. The tutorial will teach you how to work with real photo and slowly change it into a drawing look. Enjoy and good luck!
Tutorial download page: here
Saishu Heiki Kanojo manga review: here