Yeah, that's my problem, I'm really bad at that. I use a very subtle way to blend my renders (basically using texture stocks, like the lines on the left side and the white dots), and I usually get mixed reviews on it. Some people get on my case for always underblending, whereas one person (actually one of the graphics people I look up to the most) said that I'm 'very good at working with a render and adding extra little stocks over the top of the render to make it and the background come together'. It all confuses the shit out of me because everyone's opinion is so different lol.