Ok, in this tutorial you will learn to blend, heres what I ended up with after blending.

Ok, after you have your background find a render you want. I used this.


Now add it to your image. (I added mine under the color balance and brightness/contrast layer that I used for the background.) Heres what I have now.

Now select your polygonal lasso tool and set its feather to 15 pixel.

And make a loose outline around your render. (Make sure your render layer is selected)
Here is what it looks like before I completely connect the line.

When I fully connect the line heres what it looks like.

Now right click and select inverse and press backspace a couple of times till it looks blended well. Heres what mine looks like now.

Now set the blending mode of the render to Luminosity.
You should have ended up with something like this.

Thats it! Your done. Heres an example of that way of blending in a banner.