Step 13
We want to add some soft vignetting now, which means darkening the edges of the image. You could do this with a gradient but here we're going to brush it on because we don't want it symmetrical and you have more control if you do it this way. So first create a new layer then grab a soft round brush with a size of about 150px and an opacity of about 10% then set the foreground color to black. Now just brush round the top corners (the bottom ones are dark enough) make sure you don't brush over the plane and keep doing this until your image resembles the one shown below.
